It has been a really slow news week, as evidenced by Palm Sounds posting about Legos or someshit. We need more app developers so we have something to talk about! Fortunately it has never been easier to make apps, thanks to development tools like Unity.
Although it is primarily aimed at game development, it can and has been used for making music apps! In fact, this new tutorial from YouTuber Quill18 will show you in 4 minutes how to make most of the sound engine used in Physynth!
You can find lots of good tutorials on Quill18's YouTube Channel. I really like his style, he has a great personality for tutorials.
Unity is free, as long as your "company" makes less than $100,000 a year, but to export for iOS you will need to cough up $400. Then prepare to give Apple another $100 to be a full-fledged developer and run your own code on your devices. It is totally free to poke around in it though, before you invest anything!