Fancy yourself a conductor of music? SoundTracer is an app that helps you find a song in a digital library by “drawing” it in the air with your phone.
You should know this is strictly experimental at the moment, a project of The University of Oslo. All you have to do is move your iPhone or iPad through the air in a way that matches a song’s rise and fall in pitch. This video explains how it works. Good luck with the Norwegian. (Failing that, read more here.)