Keystores contain certificate information that contains security information and is used when publishing apps to Android market:
A keystore is created when you initially create your first app. Every AI repository contains its own unique keystore. As result, if you have published an app from another repository (e.g. MIT AI), and now would like to continue with AppyBuilder, you’ll have to import keystore from MIT AI into AppyBuilder.
NOTE: Before performing any imports, create a backup of your existing keystore by exporting it. Otherwise, you may encounter issues when you try to publish apps into Android market.
The export / import can be done by selecting Projects menu, then selecting “Export keystore” or “Import keystore”