14 DAY TRIAL // This is an obscure one, but I’m betting there are a few people out there who will get a kick out of this. Especially those who like to annoy their friends.
iOS 7 has this cool Compass application which uses the iPhone’s sensors to pinpoint the direction you’re facing with 360 degree accuracy. Swipe left once and you’re whisked away from Compass into something of an Easter Egg in iOS 7 – a level app.
The tool is as useful as it is cleverly designed. It uses two overlapping circles that display degree increments to show you the inclination of a certain surface (GIF via Cultofmac).
Getting the perfectly-flat 0-degree screen is pretty easy if you place the phone on a flat surface, but try doing it only with your hand. Better yet, annoy a friend by having him/her do it three times in a row in, say, 10 seconds. And bet on it while you’re at it.