I’ve been spending a little while looking at the iOS music creation landscape (because reasons I’ll get into later), and this struck me as a particularly notable app–not only does it have pretty amazing features (it’s pretty much a full-featured FM synth), but it’s also free and open sourced on GitHub, which means you have zero excuses not to try it out over the holiday season.
I only have two niggles: the developers went a little overboard with “do you like this app” prompts (which are annoying and prompted me to disable notifications, just in case) and it is a a bit crashy on my iPad mini 4 (I suspect it requires a bit more RAM than your ordinary app), but is absolutely delightful when paired with a MIDI keyboard.
Update: I read through the source code and found that it displays an annoying popup every 18 launches of the app to get you to turn on notifications, which I personally find a bit obnoxious. I get it that AudioKit might want to spread the word on updates and other apps, but not respecting user preferences is… well… debatable, especially considering that the app also prompts you for an e-mail address to unlock more presets.
The rest of the app is still great, and your mileage (and tolerance) may vary—I personally find this a bit off-putting, and if I had the time I’d submit a pull request to change that behavior.