iPhone apps for the creation of 'musical' sound.

[hypehat]

Do we know any good ones?

I got Garageband on sale for £2.50 and it's seriously amazing for what it is - the 'Smart Keyboard' thing is a better piano player then I am, has a intuitive sampler (more than my £70 piece of music software can handle), a whole bunch of cracking sounding instruments. I've been messing round creating loops on trains and things. I'd recommend it while it's cheap (think it was £13 or something ridiculous before)

Also got the Korg iKaossilator half price (still a pretty hefty £6 for an app!) but I haven't been able to mess around with that properly - lots of variety with the sounds you can create and very intuitive with the touch screen but you seem hamstrung by 4/4 loops. Will have to tinker.

What do we use, if anything?