All RAD's products are pure C at the interface level. Most of them are pure C at the implementation level, too. The one exception is that Telemetry (which I work on) uses C++ to implement the C interface, but only minimalistically.
I've had the pleasure of integrating your Granny SDK into our engine at the indie iOS shop I work at and it's been a total pleasure to work with and a perfect example of solid C interface design.
You're in luck! I ported all of Telemetry to OS X (including the visualizer) a few weeks ago, and next week I'm planning on porting the run-time to iOS. With those two big pieces finished, that should give iOS developers a full solution. There's going to be a pure bugfix/stability release early next week, and the release after that should have the iOS goodness.
