I'm working on Android application using Google Maps APIs that other person created. Project have different modules like client, client_developer, client_preproduction etc. but they all share core code in other module.
I can't understand why in
You need to sign your app with the digital fingerprint SHA-1: Android SDK Tools generate differrent certificates depending on your purposes i.e. If you need to test your app, generate a debug certificate, or if you want to publish your app, generate a launch certificate to put it on google play. You could read more here: https://developers.google.com/maps/documentation/android-api/signup
Hope it helps! :)