Hi Alena,
I am kind of new to this. Let me explain my problem.
I have built an app using appery.io which is supposed to be a standalone app without any internet requirement. So I am giving the app to the end users using bluetooth or any other mode of file transfer.
Now in this app the data gets changed at times which I do and build the new apk.
Now my problem is that I don't know which users are using my app and so I need to send an update message with a link from where they can download the app and install it. This message will come to them once they become online.
Now I was trying the Push system but could not configure it as I was unable to understand its modality.
I hope I could make my problem clear. In my apk no database, rest service etc are used.