1 Keystore to sign all apps or 1 per app?

Question

I am wondering which is the more popular option, Having 1 keystore to sign all the apps you publish, and duplicating that keystore into the cloud and locally to keep it safe, or

Answer 1

If you use the same keystore, it will be easier to make your apps work together. By having them signed with the same key, you can use a shared UID (not really recommended), or use signature based permissions. That would make it possible to export certain data or functionality and restrict access to your own apps only (using a ContentProvider or a remote service). The downside is, that if you loose the key, you'll have to republish all apps.

If you use separate keystores, it's easier to transfer an app to someone else (give them keystore and password). Additionally, you need to re-publish only one app if you lose/corrupt the keystore.

Take you pick, but I'd say: use the same keystore and make lots of backups. I would also use physical media (CD, etc) in separate locations, rather then the 'cloud', but that's your choice too.