Update - I tried using SoundPrism to control iMini and it works just fine. I don't know why the other apps don't.
Ditto on all the thank you and praise posts. I too have tried to use virtual MIDI to play iMini, but so far have had no luck after trying three different apps. There doesn't seem to be a background audio button anywhere in iMini, and even when I inserted iMini as an input in Auddiobus and the speaker as the output, I still couldn't get any of my apps to play it via virtual MIDI. The app will show it is connected in iMini's MIDI option page, but no notes will play. I even saw a video where iMini was being controlled by SoundPrism, so it should work with other virtual MIDI apps, right?