This translates whatever you put in into a bunch of different languages and then back to English. Each translation distorts it a bit and by the end it gives a funny result.
This actually takes time since it's using the internet. Press s to show the top text and h to hide the top text. If you choose to record variations, you can use the arrow keys to see them. Enter random letters and numbers for some fun! When you're in full screen, the top text may cut off.