How to sign APKs

• Android Developer page explaining the same thing as below

To test your app on a device you must export an application installer package (APK). The package MUST be digitally signed, otherwise your android phone/tablet will not let you install it.

You can use Google's debug Key and Keystore:

• The keyring is located at /home/user/.android/debug.keystore
• Hint: Go to window → preferences → android → build, you can see the keyring location there
• Keystore password is 'android',
• Key password is 'android'
• Key alias is “androiddebugkey”

To export the signed application package, in Eclipse right click on the project, select 'android tools' and 'Export signed package'