Develop Reference

Blocking Apk's from installing directly into BB10.2.1 updated devices

I port my android apps for making bb10 builds . Since now from bb10.2.1 update blackberry has introduced a new concept wherein apk's can be directly installed and can be installed in BB10 devices if the manage apps in settings menu of the phone is made ON. My question is that I wanna restrict my users from doing so and not installing the apk's into bb10 . And take download my app only from appworld.
Has anyone faced and has fixed this issue kindly tell me on how to solve the same.

Based on the Android behaviour, I don't think you can restrict users from doing so.
I haven't tried it on BlackBerry but from what you say, that option sounds analogue to the Unknown sources setting under Security settings on Android. If the user enables the installation of applications from unknown sources on their phone, there is now way to prevent the direct install of the apk (by adding something to your apk or any other way).

There is no way to restrict it to BlackBerry World only. If they get the APK, they can load it directly this way. There may be other ways around it though.
If, for example, your app is for sale and people are side loading a pirated copy, you could change your app to be free, and put some advanced functionality in your app behind an in-app purchase. That way they'll be forced to go through the storefront at some point to pay. This takes bigger changes to your app though, and the IAP implementation is likely different between BBW and GPlay.
You could also put in a version check: when your app launches, it checks a special file on your web server to see what the latest version of the app is. If they don't have the latest version, it doesn't let them use the app until they upgrade. This won't prevent side loading or piracy outright, but you can put out updates often enough to make side loading very annoying. When they are roadblocked and told to get the new version, you can link directly to the storefront to encourage them to get the latest version there.
Thirdly, and lastly, if you port your app to a BlackBerry 10 native, cascades, or WebWorks app, the app file is fully protected and can't be pirated or extracted from BlackBerry World (since the platform is secure). That will 100% protect you from piracy on BlackBerry 10.
I hope this helps!

How to identify if the new apk is installed?

I'm creating an android library that will be embedded in to application source which will be used for recording some analytics information on the server. I wanted to find out if the user has upgraded to a new version of the application(not the library) using SDK API. I'm trying to avoid having the application developers change anything in the manifest to indicate the version change. I already have a mechanism to identify each device on the server. In this case is there a way to identify if the .apk is upgraded when the tries to contact the server?
So far I found PackageInfo.lastUpdateTime is changed. I thought PackageInfo.signatures content will change too, but it is not changed even when I change the application code. Appreciate any help.

Why not just send along BuildConfig.VERSION_CODE? If the value is different than the last value received, it's been updated. For an application to be updated, the version code must be at least as large as the previous version. To be published on the Google Play store, the version code must be increased.

add the authentication procedure and security to android app. - Android

I need to increase the security of my android app. Actually my android app. will not be for Google play Store (which provides some licensing options to protect your app.) it will be used for some local companies that used the same app (Desktop app). However, I want to support two versions for my app. which are:
Demo version: for testing aims (after the given period end, the app will stopped!)
Actual version: this if the user want to pay for the app.
What I need:
To increase the security of my app. from installing it another time or on another device for the same user!
For my code I used ProGuard which is a tool provided by Android that lets you obfuscate (make harder to read) your code during packaging. cause there are many reverse-engineering application that used for unpacking the compiled code and viewing the source code (actually I tried some of them and its really amazing to restore the sourse code from .apk!) ..
I think to use the MAC address of each device the app. installed on and then store it into internal database and generate a number form it (in somehow), then ask user enters it (which I the one who knows this number and provider for it) if it is true, the app run else not. But, it's just idea I do not know how this can happen or even from where I can start or even also if that will help!
I tried also SharedPreferences But this does not help!
Actually I do not need for external database on server to read the username or the password for eligible users for app. I need to do that by my app. itself!
In sum please,
How can I protect my app from installing many times for same user or continuing using after testing period ends, etc. (I mean make it more secure)!
any ideas, any suggestions, any useful examples or sites are also desirable.
Sorry for this long question,

Android/iOS Apps Crashing, do they need deletion for new update to occur?

I've got a development partner who says that in order to fix bugs that cause an application on iOS & Android to crash on load that end users need to delete the original app and re-download the new updated version. Are they for real? Shouldn't it just be incorporated into a standard app update and work like any other update?

The answer depends on how your app was distributed. If you just sent out a link like http://www.mysite.com/mytestApp.apk, it's easiest to uninstall. If they're updating via the Google Play Store, you have to set your version number higher than the installed version. Users can then get the newer version more seamlessly. I haven't done an ad hoc distribution with iOS yet, but updates via the app store seem to work similarly to the Play store. Users get a notification and can then update if their device meets the required specs.

Usually an update should resolve these issues. However, I have seen rare instances where users running older apps will need to uninstall/reinstall to get the new version of the application working. Like I said, these are rare instances where some major configuration has to take place. It's not something most updates need to do.

Creating A time Bound Trial Version Of an Android App

I have seen so many threads on creating a time bound trial versions for an android apps but none of them seems to fulfill my purpose.
Few days back i Launched the paid version of my app and now I want to come up with trial version which i dont want to be crippled from any side. So i want to have a time bound limitation on the trial version. I have created a different Package name for the same. Earlier I was using LVL and now also I am using the same except that i created new license library and changed the
setValidityTimestamp(extras.get("VT"));
to
setValidityTimestamp(String.valueOf(System.currentTimeMillis() + (5* MILLIS_PER_MINUTE))); in ServerManagedPolicy.
so that i can test if trial version works for 5 mins and then give me the license error. I published it on the app store , downloaded it and then found that it was still working beyond 5 mins. Now i have unpublished it. Can someone help me in creating the better time bound application which a user can run for a week (say). Besides he should not be able to uninstall and re-install it and then again use it permanently. I know if i can write the info to some external file but again the file can be deleted from sd card and application can be made accesible to the user free for lifetime.
Regards
Pankaj

Within the current capabilities of LVL, and the degree of user control over your average handset, there is currently NO way to do this without a server-side component. Once your app is uninstalled all traces (except, as you pointed out, files you may write to the SD card, which are user-visible) are removed, so the only way to check for an uninstall/re-install is to generate a consistent, device-specific identifier and check with a server component that will either reject this as a re-install or accept it as a new time trial. Even this can possibly be spoofed by a dedicated customer (depending on the server-side component behavior), so you would need to engineer your software so that your server-side component is a necessary part of the process (i.e. it isn't just a license check, it is actually part of the application's functionality).
If you come up with something that works I'd love to hear about it, but I'd say you're out of luck.

#Femi is right, you need a server side component to make always work. What I tend to do is publish only a free version, and teh user buys the full version as in-app-purchase. The IAP server is your server side check if the use purchased the upgrade or not. You can store a pref on first use to know when the user started using the app. If users uninstall and install again your app, they get a new trail period, but this is annoying, and few will do it to save a few bucks. If you add a message in the app where you ask user nicely to upgrade, or have ads that are removed once you upgrade, it is a good enough solution.