While trawling through the endless "apps" that add functionality to the iPhone I came across "CameraBag"

It has a bunch of quite useful filters that you apply to images taken on the phone.

Yes this is a very nice toy......

I also downloaded "Ocarina"

You blow gently into the microphone and change notes with different finger positions.

It produces quite a nice sound not unlike an Andes Flute. It's basically a real instrument as you can play any scale in any key.