Here’s a brief but important advice for Android app developers: starting with your first app, prepare for the situation where a company wants to acquire one of your applications. Use a unique signing key (alias) for each app! Else you’ll be forced to either cancel the acquisition or hand out the key you use for other apps as well.
Android requires that all apps be digitally signed with a certificate before they can be installed. Android uses this certificate to identify the author of an app, and the certificate does not need to be signed by a certificate authority. Android apps often use self-signed certificates. The app developer holds the certificate's private key.
I hope this post might help to avoid a similar situation for other developers.