Which framework to use to make simple animations over a camera view

in my Application I like to use the frontcamera to display the user on the iPad/iPhone. This is already working. Now I like to have a simple transparent "HUD" floating over the cameradisplay. It's just a circle which sould fill itself, so it is quite a simple animation. Since I am new to iOS Developing I am not sure which framework to use. Unfortunately there is no canvas like in android/html. Can you please recommend a framework for doing the animations?

I would be very happy for a nice start into my next assignment!