Moving/copying an Appliction from one Tab 4 to another Tab 4 How do I copy/move an application installed on one Samsung Galaxy Tab 4 to another Samsung Galaxy Tab 4.  The application is no longer available on Google Play Store.
Multiple ways, depending on whether you only want to copy the app – or the data along:


you can use adb backup from your PC to backup the app from the original device and restore it to the other. For details, see:


Is there a minimal installation of ADB? (you will need that on your PC)
Full Backup of non-rooted devices (for ADB Backup itself)
How do you extract an App's data from a full backup made through “adb backup”?
our backup tag-wiki

without a PC being involved, the very same can be achieved using Helium - App Sync and Backup on both devices
there are several apps to extract the .apk files of installed apps. These can be used then for side-loading the app to the other device. Several suitable candidates can be found in this list.
You also can check on alternative markets whether the app is available there.