http://www.amplitube.com/ipad for more information.
Watch how easy it is to use Inter-App Audio in GarageBand with apps like IK Multimedia AmpliTube for iPad. See how Inter-App Audio works in iOS 7.
About Inter-App Audio:
Now your music creation apps can make beautiful music together. With Inter-App Audio, apps can share their audio streams with other apps. For example, an app like AmpliTube for iPad can share its audio stream with GarageBand which uses the stream as a track to compose a song as you see in this video.