You can also use Keynote to create simple animations. Now I should mention that if you have the Mac version of Keynote you can do a lot more with animation, but with the iPad version you can still do some pretty cool stuff.
Keynote has some built in "canned animations" but for today I just want to focus on the Magic Move transition. Basically if you have the same object on two slides and you move the object on the second slide Keynote will animate the path from the first slide to the second slide.
How can you use this?