Photo hunts are one of those "no instructions necessary" kind of games that can be played alone or with friends. As such, they're hugely popular both online and off. If you're familiar with any of the variety of PC games or touchscreen bar games, then you'll know what just what to do when you pick up 4Bugs from Root9 Medialab.
iPhone and iPad apps tagged "photo hunt."
Everest Keeps You Glued to your iPhone
Everest: Hidden Expedition is one very addictive seek-and-find game. The first iPhone app by developer Big Fish Games is a keeper with great graphics and truly addictive qualities.
The game's objective is to compete against three other teams in reaching the summit of Mount Everest.