How do I end on a different frame than the start frame with a UIImageView animation?

Question

I am creating an animation using UIImageView.

I assign the start image with initWithImage because the animation isn't supposed to start immediately so this is the static image that is displayed first. However, once the animation is done playing, this image (the one I assigned with initWithImage) is also the one that that displays again.

How can I set two different start and end frames and have them both be "pausable" (meaning, if I wanted, I could let either be the remaining image on the screen)?

Thanks.