Here are the features that make it one of my most-used apps:
Stats: The AllTrails app offers a record function if you want to keep track of your hiking stats, including time, distance, miles-per-hour, and elevation -- and see your progress in real time. You can also add "waypoints" and photos if you want to record particular moments along the way.
Extras: There are different map overlays you can apply, depending on what you need. A satellite feed, road map, trail map, contours. You can also see "waypoints," or points of interest, and photos that others have marked along the trail.
Record-keeping: If you're really mean business, using this app every time you hit the trails will allow you to build a profile that documents your lifetime stats, including miles hiked, elevation gain, moving time, and personal bests.
And if you really, REALLY mean business, you can upgrade to the pro account for a fee. This will let you download maps for use offline, design and save custom trail maps, keep track of your favorite trails and access more map overlays and layers.
The AllTrails app was a game-changer for me. I encourage you to check it out.