This is the one must-have GPS app for adventure travelers. EveryTrail records your route as you hike, bike, run, climb, paddle, ski, or move in any other way. It works anywhere in the world with satellite reception, whether you're in a city or on the Annapurna Circuit. EveryTrail will plot your route on a Google map, and keep stats of your distance, elevation, and speed. More importantly, you can use the app as a resource to find trip reports from other people on great nearby adventures, and get directions to the trailhead. There are upwards of 500,000 trips in the database, and more are constantly being added. The app also lets you upload and share photos from your trip on the fly.
Price: Free. The $3.99 pro version includes videos and eliminates ads.