Develop Reference

Renamed .apk package still overwrites old filename app when installing on my Android phone

Note that this question does not concern Google Playstore - I am downloading and installing this apk package from my own website.
I have an existing apk file that I can install and open on my Android phone.
Now I want to use the functionality of that old app in a new and similar app, but one that uses a different app name and logos.
I no longer have the old app source code, and I didn't create it in the first place (I subcontracted the app development to a coder who is no longer available).
So I opened the apk file using apktool and located the png image files that are used. I edited these and saved them in the same location and using the same filenames.
Then I edited the strings.xml file to change the app name text to the new file name.
Then I rebuilt the app, re-signed it using uber-apk-signer and uploaded to my website with a file name that is different from the old apk file.
When I download this new apk file to my Android phone, it prompts that it will replace the old app, even though I have changed the app name and apk filename. When I install this new app, indeed it does overwrite the old app, and I can successfully open the new app with the new logo.
My question is: What parameter/file do I need to edit in the decompiled original apk so that the new apk doesn't overwrite the original app when I install it on my Android phone? I want to be able to install both these apps, because they have similar characteristics, but will be used in different industry sectors (one is for the educational sector and one for the agricultural sector - both are simple charity apps to be used in the country of Myanmar (Burma).
The original apk is at www.teachersimon.org/simon.apk and the new app is at www.teachersimon.org/farmersimon.apk
Thanks!

For this too work, you need to change the package name e.g com.example.appname and the applicationId stored in the app's build.gradle file. Good luck!

Install APK from site without downloading

Until now, I only develop apps for myself or for close friends.
I don't sell apps so I'm not interested in Google Play.
So, I upload for a personal site I have, give the link to my friends,
and they download the APK.
Next they install the app and delete the APK for saving memory space.
How can I install directly my apps from my site without download the APK?
Thank you

APK shouldn't be taking that much space but what you can do is this:
1) In your MainActivity, have a method where you search for APK file in the phone external storage. (the example searches for ".pdf", change the extension to ".apk")
2) Then use a APK parser library to get the package name of the APKs found.
3) If the package name equals to your package name, delete that file.
Make sure to call that method on your onCreate() of your main activity.
Hope this helps.

Changing display name of an Android app by modifying its apk file - (Android 5.0)

I am trying to change the display name of an Android file (the name shown on the screen once the app is installed). I only have the apk file*.
When I unzip the apk file, it's partially binarized. I know that to change the display name, I have to change the AndroidManifest.xml file, but that file is partially in binary.
If I unzip an application, change something (or nothing!), zip it back up, sign and zipalign it, the application does not work anymore. It doesn't install, but crashes while trying, claiming Parse Error - There was a problem while parsing the package.
If I unzip the application using ApkTool, change something (or nothing) and rezip it using the apktool b apkFolder -o changedApk.apk, then sign and zipalign it, the app does install, my changes seem to be present, but the app crashes the moment it opens up. The stacktrace seems to indicate that the following is the problem:
F/monodroid(12679): No assemblies found in '(null)' or '/storage/emulated/0/Android/data/Geocortex.App/files/.__override__'. Assuming this is part of Fast Deployment. Exiting...
If I rezip the application using the apktool b apkFolder (thus to place the changes in the original apk file), sign and zipalign, the application installs and works, but none of my changes are present. The last modified date on the apk actually doesn't even change, so it seems like the tool does nothing.
ApkTool seems to have been successfully used in the past by many others to do the same thing as me, but now I am wondering if perhaps it wasn't updated to the Android L version.
I also noticed that the original unchanged apk is about 3 mb bigger than the output from both the apktool and the regular rezip. As another side note, I am using the original key, keychain, password to resign the app.
Does anyone know how to do this, or why the application might be crashing? Does the apktool work for Android 5.0+? Any insight is greatly appreciated!
*Details about the source of the apk and my authorization (as requested by Chris in his comment): This particular application belongs to the company I work for (so yes, I do have the entire source code and could change the AndroidManifest.xml file there). However, this application is distributed to our limited clients manually. This application does not exist in the app store and every version is manually changed to suit a certain client's desires (e.g. specific app names or icons that match their company). In order to alleviate some of the developer's work load, I am creating a Windows Program that can do all these changes automatically and the work for our team would be as easy as having to type in a new name in a textbox. At the end of the project, I plan on having a Windows tool that can take the current version of our application (in its apk format), change the app name or display icons which were inputted in simple text fields, and output signed and zipaligned application that can be easily sent to our customers.

In playstore can we have two apps with same name with different package - Android

I've upload application on google play store with my own package name.
Later client want to change the package name.
I've searched but i got that, not able to change package name after publish.
what can i do for this?
and
In playstore can we have two apps with same name with different package?

In playstore can we have two apps with same name with different package?
Yes, you can have multiple apps in the play store with the same display name, but they have to have different package names (and the play store won't actually allow a second app with the same package name as another even to be uploaded)
what can i do for this?
You cannot change the package name.
You can change the package name in your dev environment and upload it as a new app. All your ratings and download numbers will not transfer.

You can't. As stated here, seems that's one of the few things you cannot do.
Choose a good package name
Make sure you choose a package name that is suitable over the life of
your application. You cannot change the package name after you
distribute your application to users. You can set the package name in
application's manifest file. For more information, see the package
attribute documentation.

My Developed Android App Was Replaced When I Install Another App

While developing android apps, I found out that why previous apps was replaced when I installed another app using apk file.
The apps have different names, labels, but the same package name. Is that ok?

take a look at your package name. The package name must be unique. May thats your problem

The apps have different names, labels, but the same package name. Is
that ok?
No, it's not Ok. The package name is how the system uniquely identifies one app.
for example you should/could your packages name as:
com.jrgalia.app_1_name
com.jrgalia.app_2_name
com.jrgalia.app_3_name
etc...

To be very specific as why your app got replaced. All applications will be stored in /data/data/package_name
If you do adb install then the folder and its content will be replaced by your new operation, that is why while uploading to google play it makes sure package names are unique.