There apps that change the way of how we create melody and harmony. Such apps are not trying to recreate classical way of playing on musical instrument but bring together new tools like multitouch screen and easiness of use even for absolute beginners.
Gestrument is such an app. It brings new way of playing on the iPad. You swipe your finger and get the music. You have up to 8 notes/instruments playing same time. Each note value and length depends on the position of your finger on the screen. With such grid you get very interesting musical ideas from the first minutes of playing.
Gestrument comes with preloaded instruments for beginners and provide powerful tools like Virtual midi out and Audiobus support for more advanced iPad musicians.
Spend some time with this app and you'll definitely find new inspiring musical ideas. Don't forget to hit the record button in your DAW before playing ;)
And it is better to see the app in action, here's my video review of Gestrument.