Developer Avi Bortnick released Echo Pitch last December, as a unique multi-delay effect for rhythmic exploration with pitch-shifting. Unfortunately it only did any of that when you had a hardware audio interface for input. Reader Steve wrote in to let me know that it now supports Audiobus and Inter-App Audio, so you can use this iPhone app with all of your other apps!
Echo Pitch iTunes Description:Echo Pitch pitch-shifting multi-delay for iPhone. Echo Pitch has 4 delays where each delayed signal can be pitched one octave up or down in 1/2 steps, and can function as a 4 voice harmonizer. Echo Pitch also has a built-in looper, amp simulator and reverb. Each of the four delays can be routed into the other for incredible, swirling, ambient washes and otherworldly sounds.
Echo Pitch works best with an iOS audio interface, such as the Fender Slide or iRig. Echo Pitch is also Audiobus and Inter-App Audio compatible (for IAA, launch Echo Pitch first).
Brought to you by Avi Bortnick and Maximos Kaliakatsos-Papakostas.