Been having a blast with iReal Pro providing backing tracks for my improvising with a WX11. As is often the case with apps which really interest me, got thinking about all sorts of feature requests. Won’t bore you with the list, now. But there are two features which could really up the game for iReal Pro, in somewhat related ways.
Basically, they have to do with a broader workflow. My focus is on iOS but they could also work well on macOS. (Not on Android, though.)

A very important feature of recent iOS apps is AUv3 support, which greatly simplify our workflows. Whether an app is a host or a plugin, it makes it much easier to integrate it with other apps. For instance, if iReal Pro were an AUv3 host, it’d be possible for me to solo using a softsynth within the app (say, YONAC’s Kauldron) and record everything together. In fact, it’d open the door to MIDI recording, which would be a huge benefit in terms of analyzing solos and such.

My other big feature request may be more of an edge case but makes a great deal of sense in a broader context. It’d be great if iReal Pro could accept some incoming MIDI CC (or notes on a specific channel) as triggers. You send it MIDI messages and it starts, stops, speeds up, transposes…
My edgy edge case is to “transpose on cue”, using a MIDI pedal. Been playing modal and being able to switch to a new chord on demand would bring things to a new level, for me. Might be able to hack something together with some other apps, after exporting the MIDI (or even the audio) from iReal Pro. But my dream is about having more interactions with iReal Pro the way you might with other musicians. It’d be through a pedal instead of a nod, but it’d work just as well.

So, this may sound a bit crazy but… think about it. With some relatively simple additions, iReal Pro could feel a whole lot more responsive.

As for ways to code these features in, there are more and more examples of AUv3 and AU MIDI, out there, with some documentation on how to make things work. Sure, it’d still be a significant project. But someone might take it on, eventually.