The app has 3 widget icons that dial the USSD codes to check you text, call and goodybag balances.
It also adds the Data / MMS (APN) settings for the giffgaff network so you can surf the net and send MMS. And Allows you to easily delete other APN settings that may conflict with giffgaff.
Once GiffGaff exposes API's for balance checks we'll update the app to have a widget displaying the balances.
This is a beta build so it may contain a few bugs.
NOTE: It requires permission to make calls as it needs to dial the USSD codes. You are not charged by giffgaff for these, and the app does not make any other calls other than balance checks via the USSD codes.
This is a beta release, so may have a few quirks in it.