Today I find a new software in AppStore named “iFog”. When I opened it, just find a simple photo of rose flower as below :

But when I puff into the iPhone microphone, wow! iPhone screen covered with fog? It’s really interesting, huh? Now you can write down on it and you may want to play tic-tac-toe with your friends!
But the main point of this app was discovered when you write something on the iPhone screen, yes you can’t see what you write but when you puffiFog on Youtube into mic & make some fog your writing appears on the screen as you can see in following screen shot :

if you familiar with the iPhone user interface (buttons, etc) you found that the UI of this app is a bit differ form what you seen before it may be another point of interest for buying this app!
But iFog didn’t support Multi-touch, I think they should add this functionality in future updates.

Below you can find a video that demonstrate iFrog: