iOS OpenGL ES 2.0 drawing and animation

Once I had to develop an application for my job that let the user draw his/her signature and then watching it animate to become straight lines.
The Funny thing at that time was that I had never touched iOS!
So to speed things up I coded all the logic in C++ and then wrap it in C to be able to call it from Objective-C to reduce at minimum the coding in Objective-C.
It worked great!