To tell the truth I've been using a hackintosh in the last weeks and I was looking for an app like that! I tried creating a cape but how do I put multiple images for the frames? Can you send me yours so I can have a look?
You essentially create a 32x32px(or the size of your cursor) by as many frames you need. I think 24 frames is maximum though. Place the images center or in a corner. Just make sure they line up or the cursor will jump a little.
I couldn't quite figure out how to let the animation "meet" so that it was a smooth operation. I bet you can.
I have as you might have guessed done a cape based on your cursors for myself only. I can upload the cape and send you a private note with a link in it.