How about a chat on your phone that doesn't need wifi or 3G? No, this ain't an April Fools'joke, but rather a revolutionary new way to communicate.
Think of every time you were somewhere and had no connection: music festivals, camping trips, really crowded areas... FireChat eliminates the need for wifi or 3G to chat to people who are near you as it uses peer-to-peer connection and bluetooth instead. There are two separate chat rooms, 'everyone' (any users around you) and 'nearby' (people up to 30 metres away).
The app is fairly new, so a hiccup every now and then can be expected, but I thought you guys should know as soon as possible about this amazing new technology! Of course, it comes for FREE!