Use the search keyword "Ookbee Buffet", on iOS/Android/Windows Phone/Windows 8/PC.
Now, signing in gets easier via Facebook.
Extend the validity Click on the "Compare" to subscribe to a Buffet package, or extend the validity period.
Click on the "Store" menu. Then, choose your desired items and click on the "Add to Library" button. You are free to choose as many items as you want.