I have one called "offline topo maps" and dan1554 here on the board has a similar but better version. it's cool and simple.
Weather apps: I have like 4 of'em (nerd alert), but my favorites are the NOAA HD and "living earth". NOAA for regular radar maps, and forecasts....Living Earth for the sheer beauty of the app - it's simple, has a gorgoues UI, and actually shows you the weather info you want at a glance.
Games...well...to fight off "old-timers"...I'm hooked on Words w/Friends. I have all the others. (those pissed off birds, the one with tiny wings, Where's my Water is cool and cut the rope) those are my faves.
News...I have the CNN and AP apps. nice to check in on when you hit Green River after three days in the Swell.
Wine: for you winos out there...get the WTSO app. (I've gotten Silver Oak for $38/bottle shipped - 'nuf said. )
HAM: ARRL's repeater locator and Database + the General exam prep.
Travel: I70 cams, SAS survival app.