If you’ve been around on the internet for any length of time, you’ll have probably heard about a site called Xtranormal, which converts text you enter into a simple little video starring cute animal characters. (If you haven’t heard of it, go and have a play there now, it’s fun.)
Tellagami is a new free iOS app that does something similar. I say “similar”, but the two are not in the same league. Tellagami is very simple, and its features limited. That doesn’t mean you can’t have fun with it, though.