I finally got an I Phone, and am looking for suggestions for musical apps such as tuners, metronomes etc. to add.....there seem to be lots of choices, which ones are best?

I have the Cleartune app as a tuner, works well. Tempo as a metronome.
Just got garageband for my ipad and iphone. really cool, great fun.
Also have Tabs for song chords and instantbeat for rythmns.
Finally, I bought a Eric Marienthal lesson app. It's very, very good. I use it for my students, and yes for me too.