iphone apps

Heres one for you,
I'd like to know which iPhone apps you'd recommend for cycle computing/gps/training....pretty much everything.
I'm Living in Peru and don't really do much XC or Road anymore, mostly trials (for fun) and for work I guide hippies (tourists) down the old mega avalanche course and glaciers (and hope they don't die on my watch) so most of my riding is DH/Freeride like but i'm keen to map and track my rides and have some form of computing ability.
the majority of apps seem to be geared to hard core road/XC riding, that would be semi useful to me but since I don't do much of that (the roads here are terrible, so I left my road bike at home) some other form of computing/gps app would be preferable...I just have not found it!
Why not have a feature on useful apps for various types of cycling situations/disciplines?

P.S. Have ridden the Swiss alps (and LOVED them dearly...) but the Andes OWN!!!!