If you want to take vengeance on the driver who just cut you off without signaling, then you need the Drive Me Crazy app. This app lets you report bad drivers directly to the DMV and the insurance company.
Users simply need to key in the license plate number and the offense. The Drive Me Crazy app also works in reverse, letting you report good drivers and contact "cute" drivers who are also using the app. Although this app seems cool, it also seems too easy to abuse.