I think the name says it all. The main screen has the Android robot. You drag his head up and the further you drag his head up, the faster the phone vibrates. The vibrations start with delayed vibrations, then the further you drag the Android head up, the shorter the delays until you get to the highest setting, which is a constant vibrate.
You can also send DSMS (Dildroid SMS) messages to people with Dildroid installed. The types of "vibrations" you can send via DSMS are a "Slow massage", "maximum pitch captain" and "orgasmic crescendo". I might install it on a friend's phone, and send him an "orgamsmic crescendo" when he's in a lecture.
The app is free, and can be found on the Market by searching for "Dildroid".