Great news for customers on Three UK who use Windows Phone 8 devices, you finally have access to an official My3 app. It was just released this morning to the Store and is a free download.
This new app will allow you not only check your allowances, but also get support, check add-ons, check your bills and get quick contacts if you need to call anyone at Three.
So, if you are on Three and have a Windows Phone 8 device, why not download this new app right now.
UPDATE: There seems to be a slight issue where allowances state you have run out, this has been reported and should be fixed soon.