Klevgränd has released Haaze, which they describe as a stereo spreading tool. They tell us that, by splitting the input signal into 16 different frequency regions, spanning from 20 Hz to 20kHz, Haaze can add different amount of stereo widening to different frequency regions. This makes it possible to transform a mono track into a natural sounding stereo track (by for example keeping lower frequencies in mono while spreading the higher ones).
Haaze is compatible with both iPhone and iPad (AUv3), and also available for desktop as AudioUnit and VST.
Pricing and Availability:
Haaze for iOS costs $4.99 and Haaze for desktop costs $12.99. (Introductory prices with 35% discount)