After your first sign in jump to „settings“ and enter your mobile number (the number will be saved automatically). After completed action the app is ready to use.
To use a complete other callingcard you need to sing out. You'll find that action in “card data”.
We're trying to display the provider and product name in “card data”. Information without guarantee.
iPhone at least iOS-Version 4.3
Android at least Version 2.3.3 1000 Mhz, 512 MB RAM
Not available now.
Let's try your card (serial and pin), if it is not running (displaying that serial or pin is wrong) it's not supported yet. :)