So I am a bit confused! I just found out opengl es 3.0 was a thing and a ton of questions flowed into my mind... if you have any thoughts let me know.
I just make a 3.0 context, if that fails with nil then fall back to a 2.0 context. For instance, iPad 2 will fail the 3 context and make the 2 context. This way you will not need to check on a device by device basis.
OpenGL ES 3 is super set of 2. Migrating code is much easier. Mainly just name changes of functions and enumeration constants.
I swapped my 2.0 code with the version 3 headers. I then saw the compiler errors and fixed them. After that for compatibility, the context has a property called API which you can check for 2 or 3 to make appropriate calls if there is enough of a major difference. So, I could check for API and use the old code if necessary -- compare with git for instance. All the shader code from ES 2 is compatible with ES 3. Much easier transition than from OpenGL ES 1 to 2.
Hopefully, we get the older devices to drop out on iOS 10. Like the 5C and iPad 2 -- the performance difference is so great its difficult to program for the scope of devices.
Hope that helps.
btw, here is a useful link per Apple:
