Develop Reference

How to get list of downloaded apps (paid/free) by a user from Google Play?

I recently came across this app Purchase Apps, which is somehow able to retrieve apps I've paid for in google play after I signed in using my google account.
I'm trying to find out how it is being done as I want to build a similar app, but for the free apps which were downloaded.
However, I can't find which OAuth API Scope was used for retrieving that information, even after going through the entire list of APIs.
EDIT:
I'm putting a new bounty on this question, as suggested by a similar question I've asked about here, and because here and there I don't see a real answer about how to do it, and what can be done with it.
I'd like to refine the questions into multiple pieces:
What is the API that can be used to get information of purchased apps? Where can I read about it? Please show a full, working example of how to do it.
Can it do more ? Maybe perform search? Maybe show free apps that were installed? Maybe the time they were installed and uninstalled? And the categories of those apps?
Are there any special requirements for using this API ?
EDIT: I'm putting a max bounty on this, because no matter how much I've read and tried, I still failed to make a POC that can query the apps from the Play Store that the user has ever downloaded (name, package name, date installed and/or removed, icon URL, price...), including both paid and free apps.
If anyone finds a working sample, show how it's done, and also show how you've found about it (documentation or anything that has led you to the solution). I can't find it anywhere, and the current solutions here are too vague for me to start from.

Issue is resolved. The exploit has been closed.
We will be closing this bug due to being logged in a Preview version of Android. If the issue is still relevant and reproducible in the latest public release (Android Q), please capture a bugreport and log the bug in https://source.android.com/setup/contribute/report-bugs. If a reply is not received within the next 14 days, this issue will be closed. Thank you for your understanding.
Latest update:
This is a bug and Google will address it in the next update.
We've deferred this issue for consideration in a future release. Thank
you for your time to make Android better
This answer has turned into a conglomeration of ideas and been edited to include information from discussion in the comments.
The androidmarket api, would be a customised api written by the developer. It's not available to the public.
To address your concerns in the comments. The developer would have utilised the current apis available through Android Developer and Google to create a project that manages all of these.
As for accessing Full Account Access, I'm not sure exactly how these developers have achieved this.
I'd recommend using the AccountManager, which is part of android.accounts, has access to credentials and a method getUserData. The account manager has access to passwords and is capable of creating and deleting accounts. This, possibly used with Content Provider
See Udinic/SyncAdapter Authentication.
To reply to your comment:
This blog should help you to get started. Write your own Android Authenticator.
How these apps actually work, I cannot tell you. They may also have different implementations (unless they're a collaborative effort behind the scenes, they most certainly will be different).
One guess. Firstly use GoogleSignInAccount with com.google.android.gms.auth.api.signin.
There a definition for scope, to determine the extent of the permissions the app is granted.
Using requestScopes(), the
public static final String PROFILE
.../ It lets your web app access over-the-air Android app installs.
For example:
GoogleSignInOptions gso =
new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
.requestEmail().
.requestScopes(new Scope("https://www.googleapis.com/auth/contacts.readonly"))
.build();
If full access can be gained a list of all apps used by the account holder can be found and compared to what's on the device.
Package Manager will retrieve a list of all apps currently installed on the device.
PackageInfo provides the details about the app.
INSTALL_REASON_USER will also filter out apps that have been actively installed by the user.
You might want to look at com.google.firebase.appindexing and Log User Actions. Different actions can be tracked.
The users account history is found at https://myactivity.google.com/myactivity.
A helpful link is the OAuth 2.0 Playground.
This github repo node-google-play, using node, is current and will call Google Play APIs. As did the archive that was used as an "unofficial" api, android-market-api, to query the market place.
App 1
The app claims to use the following permissions:
Version 2.1.8 can access:
$ In-app purchases
Other
receive data from Internet
view network connections
full network access
use accounts on the device
prevent device from sleeping
read Google service configuration
Noteworthy, the app doesn't set any permissions when there was a basic, install. I was unable to use any of the features, as I have no paid apps. So for the initial search - there were no permissions needed, which would indicate the app didn't have access to my account.
I checked the permissions - there were none set. So the only thing required was to accept the pop up, as displayed in your question.
App 2
The other app you refer to that does the same thing is more upfront about what is being accessed.
My Paid Apps
SECURITY/PRIVACY NOTICE
The first time you run this app, it will ask for full permission to your Google account. This is unfortunately
the only way to access the required information. No personal
information is stored, no information about your apps is shared with
the developer of this app, nor shared with any third parties.
Everything is kept on your phone only.
I've gone into detail over these apps in this blog post, which was for a university capstone project (no monetary gain). I'm inclined to think this is an exploit in the API and not status by design by Google, as there are no API calls to fetch purchases of apps other than the developer's own app. I hypothesize it's a zero day exploit, in which case there's no legitimate way to access this information.

In case of one of these applications (My Paid Apps), after checking the network traffic it is pretty obvious that it does use the Store's Account page to retrieve the list of paid applications.
Now, the mechanism it uses is the same mechanism that Google Chrome currently, and Pokemon GO supposedly at a point in time used.
In a nutshell, steps to do so are as follow:
Login:
What the mentioned program do for the first step is to log the user in and get access to the user's access token. To do so, it uses the android.accounts.AccountManager.getAuthToken() method. (See more: AccountManager)
However, as for the token scope, oauth2:https://www.google.com/accounts/OAuthLogin is requested.
It might be important to note that based on the OAth2 documentation from Google, this scope is not valid; however, it seems like a valid scope for Google OAuth v1.
Converting the newly retrieved access token to a ubertoken:
Now, what actually ubertoken supposed to do, is unknown and there is no official documentation about it. However, it was seen in the wild to be used by chrome browser to login users.
This is done by requesting the https://accounts.google.com/OAuthLogin?source=ChromiumBrowser&issueuberauth=1 page.
Converting ubertoken to website session:
Later on, using the newly created ubertoken it is possible to get a website session using the https://accounts.google.com/MergeSession API endpoint. After this step, the application is essentially capable of loading all personal pages that you can open using your browser while logged in; except some special pages including Payment settings.
Retrieving the list of paid applications:
Requesting and parsing the https://play.google.com/store/account page.
Following is the application's traffic as captured by 'Packet Capture':
As it is clearly visible in the picture, the end result is identical to what I get when I normally open the store's account page on my PC with Chrome Desktop:
Side note:
It seems none of these endpoints are documented as they are primarily used by Google's own programs and should be considered internal. Therefore I strongly recommend not using them in any program or code that you expect to run for a long time or in a production environment.
Also, there is bad news here for you too, it seems that the Google Play's account page only lists paid applications or special free apps (more especially OEM apps). I will try to find some time and dig deeper into the other application.
Interesting articles:
Pokemon tokens
Exploiting Google Chrome's OAuth2 Tokens

If you have root access, You can access /data/data/com.android.vending/databases/library.db
OnePlus3T:/data/data/com.android.vending/databases
-rw-rw---- 1 u0_a2 u0_a2 229376 2018-12-26 18:01 library.db
This database has all information, which app you have downloaded, which apps you have purchased, and even in which app you have done IAP.
Check ownership table, It has all information.
ownership (account STRING, library_id STRING, backend INTEGER, doc_id STRING, doc_type INTEGER, offer_type INTEGER, document_hash INTEGER, subs_valid_until_time INTEGER, app_certificate_hash STRING, app_refund_pre_delivery_endtime_ms INTEGER, app_refund_post_delivery_window_ms INTEGER, subs_auto_renewing INTEGER, subs_initiation_time INTEGER, subs_trial_until_time INTEGER, inapp_purchase_data STRING, inapp_signature STRING, preordered INTEGER, owned_via_license INTEGER, shared_by_me INTEGER, sharer_gaia_id TEXT, shareability INTEGER, purchase_time INTEGER, PRIMARY KEY (account, library_id, backend, doc_id, doc_type, offer_type))

Dealing with unofficial Google APIs is incredibly complicated territory. It's going to be possible to get this to work, but that's all I'll say. Proceed at your own risk.
The first thing you're going to need to do is get a Google Play auth token. This can be done several ways, but here's how they do it in Purchased Apps:
public static String getAuthToken(Activity activity, String userEmail) {
AccountManager accountManager = AccountManager.get(activity);
Account userAccount = new Account(userEmail, "com.google");
Bundle options = new Bundle();
options.putBoolean("suppressProgressScreen", true);
String token;
try {
Bundle result = accountManager
.getAuthToken(userAccount, "androidmarket", options, activity, null, null)
.getResult();
token = result.getString("authtoken");
} catch (OperationCanceledException e) {
Log.d(TAG, "Login canceled by user");
return null;
} catch (IOException | AuthenticatorException e) {
Log.e(TAG, "Login failed", e);
return null;
}
return token;
}
A few things to note here:
The above code must be run asynchronously. I recommend RxJava, but an AsyncTask will work.
You must supply a email for the account you want to use. I'll leave the details up to you but this is fairly easy using AccountManager.
After you have an auth token, you can now access any Google Play Store endpoint. The main one used by Purchased Apps is https://android.clients.google.com/fdfe/purchaseHistory. Another one you might be interested in is https://android.clients.google.com/fdfe/details?doc=(package name) (from APKfetch code). Here's a page with some more and some analysis. If you make a request to these APIs, you'll need to supply several headers:
Authorization - "GoogleLogin auth=(your auth token)"
User-Agent - "Android-Finsky/6.4.12.C-all%20%5B0%5D%202744941 (api=3,versionCode=80641200,sdk=" + VERSION.SDK_INT + ",isWideScreen=0)";
X-DFE-Device-Id - your device's Google Services Framework ID, obtained from AdvertisingIdClient.
X-DFE-Client-Id - "am-android-google"
Accept-Language - The device's language code, eg "en".
Now, you need to parse the response. Here's where things get tricky. These APIs returns a message encoded as a Protobuf, so it's essentially just binary data unless you have a schema (which of course, only Google has). One way to go about this in theory is to decompile the Google Play Store app and reuse their generated protobuf models with a tool like JADX.
Unfortunately, I've tried this and it doesn't really work. Protobuf model classes are just too complex for a standard decompiler. What you can use is a tool called PBTK. You'll ideally want to run this on the Google Play Store 6.1.12 APK, since that's the last version before they started using ProGuard. Do note that this program has two errors in its script that need to be fixed before running it: changing 'extracto' to 'extractor' in gui.py and removing the assertion statement on line 500 of jar_extract.py.
Now, that should output all of the response classes as .proto files. Create a folder under src/main called proto and drag the entire generated 'com' directory to it. You can delete everything that's not under com/google/android/finsky/protos. Follow instructions online to setup Gradle with the Protobuf Lite plugin.
When you want to parse a response, you can use the ResponseWrapper class, since they all appear to be contained under that.
That's about as far as I can take you. There's a good chance I got some part of this wrong; JADX is your best friend here, because the best way to figure out what an app is doing is by looking at its code. Hope this helps and happy developing!

you can get the package name of all installed apps on device and then get the information of every installed package that you find in the device from google play without any need to get to user account. there is some third party or unofficial apis to get google play apps details as json by getting the app package name. for example: https://42matters.com/
then use the received information for every package to find free ones.

i have two resources for you to consider, but first, in a word, no. there is no api from GOOGLE to let you do what you want, as these metrics arent stored in the phone, they are on the google play store servors, and google has no OFFICIAL api for the play store. you can however glean some info from these two sites:
https://www.quora.com/Is-there-an-API-for-the-Google-Play-Storeenter link description here
https://android.stackexchange.com/questions/162146/how-to-see-all-the-apps-i-have-downloaded-from-google-play-store
and this is enough to see how to accomplish this.
first, a list of what apps have been downloaded by an account is only referencable by the account. and this can be done through the play store. since your app will be installed on that users phone, this dosnt matter... you're in.
second, you will need a 3rd party API built for the GOOGLE PLAY STORE, there are some out there, check the first link.
using the api of your choice, you will send a get request, to the play store, and in return you should receive in most cases a json object to deserialize.
deserialize the object, and you will have your list. which list you get will depend on the endpoint you use, but that should be explained by/in the API itself.
good luck!

Remote update app on multiple devices NOT using Playstore

I'm trying to find a solution to do a remote update of an APK to 80 tablets. This should preferably be as automated as possible and if this can happen completely in the background without any user input that would be great. Basically what the Playstore currently do which I unfortunately can't use.
Is something like this possible without rooting the device? Any suggestion on libraries/ services that does this?
I'm running Android 4.1.1 and they will all be connected to a Wi-Fi.

You can download the new APK file to SD card, then call this to install it:
Intent shareIntent = new Intent(Intent.ACTION_VIEW);
shareIntent.setDataAndType(Uri.fromFile(new File("path-to-APK-file")),
"application/vnd.android.package-archive");
try {
context.startActivity(shareIntent);
} catch (Throwable t) {
// handle the exception here
}
There is only one thing not automatic: the final step. The system will ask the user to confirm installation.
About the MIME type of APK files, here's the wiki page.

No, in the background isn't possible without rooting or having the device's signing key at least as a standard Android APK update. The only semi-reasonable way I can envision something similar to this working is for your app to always check for/download code to run which you load using a class loader. This would be a significant amount of work and not easy.
However, if you're willing to live with some user interaction, it really shouldn't be that hard (though it'll still take some building of infrastructure). Keep a web service that returns the latest version number, compare with the current version number and download the new APK as necessary. Installing an APK programmatically has been covered in many SO questions.

Is a Trial-like behavior possible in android apps

I'm new to Android developement (I know very basic stuffs), and there is a chance that soon I'll be tasked with porting a WP7 app to Android (fortunately, I can use MonoDroid...).
Now that app has a trial functionality (see here), which for WP7 means that I can check whether the user bought it (so I can enable additional features inside the app) or downloaded the free edition. I do not want the trial to expire, I want a "free edition" of my app to be limited to certain features.
Is there anything similiar for Android? (And can it be done on MonoDroid?)
I've looked at Google Licensing Service, but I don't see how that helps me.

I would go for two apps solution. One "real" application, which contains all the functionality. Second "key" application which only check licensing.
First application will check if the key application is installed. If the check is positive then display full content, enable all features. If the key application is missing the application behaves like free version.
It is also very important to check if the private key that signed both applications is the same. Without this check someone might create their own key application and unlock your functionality. To do so consider this snippet, which I took from this blog: http://www.yoki.org/2010/07/31/creating-a-freepaid-app-pair-for-the-android-market/
protected boolean isProInstalled(Context context) {
// the packagename of the 'key' app
String proPackage = "org.yoki.android.pkgname";
// get the package manager
final PackageManager pm = context.getPackageManager();
// get a list of installed packages
List<PackageInfo> list =
pm.getInstalledPackages(PackageManager.GET_DISABLED_COMPONENTS);
// let's iterate through the list
Iterator<PackageInfo> i = list.iterator();
while(i.hasNext()) {
PackageInfo p = i.next();
// check if proPackage is in the list AND whether that package is signed
// with the same signature as THIS package
if((p.packageName.equals(proPackage)) &&
(pm.checkSignatures(context.getPackageName(), p.packageName) == PackageManager.SIGNATURE_MATCH))
return true;
}
return false;
}
This approach gives you few advantages in flexibility:
separate paid areas. You can assign sets of features to different key applications. eg. app key1 unlocks additional game levels a1,a2,a3 and app key2 unlocks levels b1,b2
time licensing - instead of only checking the existence of key application. You can query it to check if the licence is still valid. That way you can achieve time licences.

Probably the best way for you would be to use in-app purchases

Supporting Amazon and Android market (Google Play) links inside application

So one of my applications was rejected from the Amazon app store today. The reason was because inside my app, I linked to the paid version of the app on the Android market. Disappointing, but whatever, I guess everyone wants their cut...
So now I'm left having to modify the application to change the Android market link to an Amazon app store link. Not really a big deal except for now if I do that I'm left with a discrepancy when I want to upload a newer version back to the Android market. After all, it would be rather dumb to link someone to the Amazon app store if they purchase the app from the Android market.
Now we all know that it is a pain supporting/managing multiple versions of the same app. Consequently my question becomes how can I link to both at the same time? Is there a way to tell where an app was downloaded from so I can code both links into the app and thus point the user automatically to one or the other? Secondly, is it against the Amazon TOS to give the user a choice (say I pop up a dialog instead and ask the user where to download from)?
Thanks all.
Edit: Direct from Amazon customer service "Re: Link to both markets" (I wish the approval process was as fast as these guys):
For the time being, we need any
linking to point back to the Amazon
Appstore only for market links.
Linking to your website is allowed,
just not other markets.
When pointing to other apps from
within your app, including up-sells,
completion of purchase must be from
the Amazon Appstore.

Good news! Apparently the latest version of the Amazon store finally sets PackageManager.getInstallerPackageName() to "com.amazon.venezia" to contrast with Google Play's "com.android.vending". This will be the easiest way to determine if your app is sideloaded, installed from Amazon, or installed from Google.

Here's what you can do:
Complete the preparation and signing of your application.
Install it on your test device
Use PackageManager.getPackageInfo
How to do this:
public static boolean isMarket(Context context){
boolean isMarketSig = false;
int currentSig = 1;
try {
Signature[] sigs = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_SIGNATURES).signatures;
for (Signature sig : sigs)
{
currentSig = sig.hashCode();
Log.i("MyApp", "Signature hashcode : " + sig.hashCode());
// This Log is for first time testing so you can find out what the int value of your signature is.
}
} catch (Exception e){
e.printStackTrace();
}
//-1545485543 was the int I got from the log line above, so I compare the current signature hashCode value with that value to determine if it's market or not.
if (currentSig==-1545485543){
isMarketSig = true;
} else {
isMarketSig = false;
}
return isMarketSig;
}
public static void openStore(Context context){
if (isMarket(context)){
Intent goToMarket = new Intent(Intent.ACTION_VIEW,Uri.parse("market://d" +
"etails?id=com.jakar.myapp"));
goToMarket.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(goToMarket);
} else {
Intent goToAppstore = new Intent(Intent.ACTION_VIEW,Uri.parse("http://www.amazon.com/gp/mas/dl/andro" +
"id?p=com.jakar.myapp"));
goToAppstore.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(goToAppstore);
}
}
Basically, the hashCode() that you get from the app installed on your testing device will be the same one from the market. The hash code from the app store will be different because according to https://developer.amazon.com/help/faq.html, the app store signs the application with a signature specific to your developer account, so that will return a different value that what you actually signed it with.
Note: It works to open the market successfully, but I haven't yet deployed this method on the App Store, so I haven't completely tested it. I am confident it will work, but can make no guarantees, so if you use what I've suggested and it fails, please don't hold me accountable.

You can do the following things:
Check if the device based on its Manufacturer.
For ex: https://developer.amazon.com/sdk/fire/specifications.html
For writing reviews and opening the Amazon App Store use the following intent
amzn://apps/android?p=package_name
where p=Link to the detail page for a specific package name.
Ref: Amazon developer link.
https://developer.amazon.com/sdk/in-app-purchasing/sample-code/deeplink.html

As you said, you could use a boolean and then be forced to build your apps twice, so I bevelive it's not the best way.
The best way is to check if android market is installed and act accordingly: here.
Another even more complex way is to query the name of the installer of your app, using PackageManager.getInstallerPackageName. This needs extra work since the app can be installed by parallel markets even if you are on android device with android market installed, and also you must check if it's installed as debug/development (installer package name is null in this case).

What a hard way to do this. If you just want to open the market url, just check if the intent with the url for android market has any activity that knows how to handle it. If not, open up the amazon appstore with another intent.
/**
* Returns intent that opens app in Google Play or Amazon Appstore
* #param context
* #param packageName
* #return null if no market available, otherwise intent
*/
public static Intent showApp(Activity activity, String packageName)
{
Intent i = new Intent(Intent.ACTION_VIEW);
String url = "market://details?id=" + packageName;
i.setData(Uri.parse(url));
if (isIntentAvailable(activity, i))
{
return i;
}
i.setData(Uri.parse("http://www.amazon.com/gp/mas/dl/android?p=" + packageName));
if (isIntentAvailable(activity, i))
{
return i;
}
return null;
}
public static boolean isIntentAvailable(Context context, Intent intent) {
final PackageManager packageManager = context.getPackageManager();
List<ResolveInfo> list =
packageManager.queryIntentActivities(intent,
PackageManager.MATCH_DEFAULT_ONLY);
return list.size() > 0;
}
Another way is to build using ant. This way you can generate dynamically a java class with constants set to a value that represent the app market, and output different builds with ease. This however takes some learning but when you have it running, it's very easy.

I was also struggling with this, but decided that the instant success I'm seeing with my free app on Amazon warrants the time to create a second set of .apks when I make a new build. I went with the Amazon boolean flag for now, and create one common version, then a version incremented by one for the Amazon market. No other markets demand internal linking, AFAIK.
I eventually intend to code up a market chooser with a slick way to automatically figure out what to do, but there are a lot of variables - not just the market address of one app, but how different markets recognize the company name to find all apps. Some market apps hijack the main Android market protocol (e.g. Appslib and SlideMe if I remember correctly) but don't store the company name the same way. Then you need to decide where upsell links go - to the same market or to a common one (I only submitted my free app to most of the markets I use).
I am waiting for my paid app to be approved, but I am pretty sure it will be worth it to have it available on the Amazon market given how many downloads I've gotten for my free app.

Just refactor most of your project into a Project Library, and then create multiple projects (e.g., for each app store) that have only unique icon and string resources, their own package ID declared in the manifest, and then a main activity that extends the main activity that you have defined in your library.
That way, all the unique URLs can be provided by overriding, in each particular app project's activity, the virtual or abstract methods defined in your library's main activity. The library code that that displays these URLs can obtain them via a polymorphic call to each of those methods.
That way, each such specialized project will be very small, and maintenance will be mainly to your library, as described here:
Multiple Apps with a shared code base

Auto-Update for (private) Android apps

I'm developing a non-public Android app, i.e. the app won't be available in the global Android Market. The app will be installed on a limited number of clients, e.g. by using an apk file.
How can I enable an auto-update functionality in this app?
I see different potential options (I do not know if those are technically hard or even impossible to implement or if there are any existing functionalities that can be reused):
On each launch the app tests if a new version exists (by requesting a server), if so downloads the new apk and replaces itself with the new version.
Use (or develop?) a separated app or service that undertakes the update-check and replacement-process.
Use (or develop?) a private market app which has an auto-update option. This option is similar to the second one, but more generic: The market app would be connected to a repository, i.e. it would handle an arbitrary number of (private) apps.
I would prefer option one since the auto-update functionality is included in the app which needs less development efforts.

janjonas, in the company I work we had a similar problem with Windows Mobile 6.x, and we use pretty much the same solution pointed by EboMike:
The main app check if it's updated, against a WebService. It receives the current version & the URL from where download the new version, if necessary. The main app then start the Updater app, passing the URL, and quit.
The Updater do the download of the new program, via HTTP, showing to the user the % downloaded. The user can cancel the download anytime, in a controlled way, and the Updater can registry this cancellation.
Since the new app is downloaded, the Updater run the new app, and quit.

I think option one is the least amount of work for you, and actually the cleanest one too since it will go through the proper channel of using Android's built-in package installer which includes user notification and the option for the user to abort the installation if desired.
You already have it all outlined - check for a new version on a server (would be nice to give the user the option to turn that off), and if there is a new version, you could either just link to the URL with the APK (which will, IIRC, use the browser's download manager to download it), or you could download it with your app and then point the intent to your local file. Using the HTTP link is technically less work and cleaner - the more you let the operating system do, the better - unless there's a reason not to.

Enabling "Install non-market app" is still needed for any application outside the Google Play. If it not enabled, the installation process is going to ask for it and redirect the user to the Application Settings, and after that, the user can install the app.
Depending on your needs, you can delegate to a third part lib.

Some of the permissions we'll use to get this done are the following:
<uses-permission android:name="android.permission.ACCESS_SUPERUSER" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Let me explain a bit... The last, WRITE_EXTERNAL_STORAGE, is self-explanatory. With ACCESS_SUPERUSER we'll tell the system that we intend to use root privileges. READ_EXTERNAL_STORAGE will be needed in the future in order for your app to read files on SD card.
Assuming that you have downloaded the file and that all those devices can be rooted (limited number of clients, not on Play, etc.), you could do this:
String filePath = Environment.getExternalStorageDirectory().toString() + "/your_app_directory/your_app_filename.apk";
Process installProcess = null;
int installResult = -1337;
try {
installProcess = Runtime.getRuntime().exec("su -c pm install -r " + filePath);
} catch (IOException e) {
// Handle IOException the way you like.
}
if (installProcess != null) {
try {
installResult = installProcess.waitFor();
} catch(InterruptedException e) {
// Handle InterruptedException the way you like.
}
if (installResult == 0) {
// Success!
} else {
// Failure. :-/
}
} else {
// Failure 2. :-(
}

Here might be a very lame method but for some companies, if you believe its applicable, this might be very easy to implement.
Create an password screen (passwordActivity) that asks a password to access the application.
Once the password is entered, raise a flag (set a boolean value from false to true using sharedpreferences)
Place the .apk file on Google Store.
Change the password once everyone installs the app, and release a new update on Google Play Store.
Since the software is going to cache the flag value, the password screen won`t show up even the password is change. It will only show up for new installations so might need to repeat the process.
Note: This method might better fit if there is not hundreds of users using the application. And don`t forget this method is also not secure. To sum up, if you are looking a way to keep the application private and have no security concerns, this is what I recommend.

Update app
Make sure that you already have your new apk download on location
void installNewVersion(String location) {
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(new File(location + "app-debug.apk")),
"application/vnd.android.package-archive");
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}