I am trying to do animations on iPhone using OpenGL ES. I am able to do the animation in Blender 3D software. I can export as a .obj file from Blender to OpenGL and it works on
This is an old question and since then some new iOS frameworks have been released such as GLKit. I recommend relying on them as much as possible when you can, since they take care of many inherent conversions like this, though I haven't researched the specifics. Also, while not on iOS, the new Scene Graph technology for OS X (which will likely arrive on iOS) in the future, take all this quite a bit further and a crafty individual could do some conversions with that tool and then take the output to iOS.