UPDATE: If the app crashes on you, do the following - plug your iDevice into your computer, open Kuaiyong, and click the wrench and screwdriver icon on the top right (directly to the left of the heart). Let it do its thing and the app should now work.

Step 1 download:
http://www.filecenter.eu/?p=55

Step 2 download:
http://www.filecenter.eu/?p=55

Step 3 - Walkthru on how to get ROMS and gba_bios.bin once the app is on your iDevice
http://www.filecenter.eu/?p=55