Some great stuff being going on here!
I finally finished what would have been my entry for the Symmetry challenge a while back, and have just archived away my code base to refactor it all.
After a period of brainstorming/research/basic planning I am making a couple iOS/Windows store apps. They are partially heavy on the GL ES front, along with some other stuff
They're not massively beyond what I've already done graphics wise. But learning from the previous issues I've had I'm throwing away the C only ideal, and going for a light smattering of C++. The other factor is, the debug builds and whole thing itself will optionally have a huge amount of logging/diags. I already have a read-only windows console window (see AllocConsole) showing my output auto positioning itself in the bottom left of the screen, or optionally auto sized full across the entire left hand side. This window also auto-shows hides shadowing the main gl window. Later plans for a full screen GL console for debugging purposes where the windows console isn't available. Console input there isn't critical now, but could be down the line.
I'm not going for full cross platform, just enough stuff to make the other platform specific parts minimal.
Plan. Get the prototype apps running on Desktop GL, get it running on a ANGLE project desktop build to iron out desktop GL vs GL ES differences then (basically the what webgl usesa). Then get that running on "Modern UI" (metro) version of ANGLE project as I have a cheap x86 tablet i picked up on black friday. I'll use that to get the usabilty with touch screens dialled in. After that, get it running in the iOS simulator (I have a VirtualBox VM running OSX) and once at that point this is definitely happening I'll allow myself to buy a Mac to finish it off and launch it on iOS, apps in both stores
Although i'm mainly a Windows dev, I've done a little iOS/objective-c dev at work, and am doing an android project in the near future.