Smartphone trail apps can be enormously useful for navigation on trails, especially on unfamiliar paths. There are many apps available, offering a wide range of features, from simple "you are here" info to trip recording, track-back, and suggested walks.
While we still recommend carrying a physical map (and knowing how to read it), having one (or more) of these apps on your smartphone can be very handy. Most have a free version with basic features, and paid versions with advanced functionality. Some of the more popular apps are listed below. Try them out and see what works best for you.
Note: Download any apps at home and play with them a bit before heading out on a trail. Get familiar with the features you'll need BEFORE you need them.
Not an app, but important to know about. This is the database that all trail apps use as a basemap. It is crowd-sourced, with user-submitted information about trail routes & features. It is a website, and can be viewed through a web browser. Apps like those listed below will add features & functions (trip recording, for example) to the basic view of the trail information.
Open source app. Need to download maps for the places you’ll visit (states, etc.). Works offline. Most features are free. OsmAnd Plus is the paid version of the app. It unlocks unlimited maps, hillshades, slopes and more frequent updates for certain map features through OSMAnd Live.
Basic trail info, similar to OsmAnd. Free & Pro versions.
Free to download/use. Need to enable OSM layer to see trails. Limited ability to zoom in. Only for Android.
Owned by the Outside media company (which also owns the Trailforks app). Popular. Free version has basic features. Two levels of paid access for more features (including unlimited maps and offline use).
Much more of a social focus. Suggests trails to walk, with “guided tours” - reviews, photos, user comments, etc. Encourages users to submit their own reviews at the end of a walk. Several steps needed to get to a simple (non-guided) navigation screen. Free & paid versions.
Activity-focused, mostly runners and mountain bikers, with a significant social aspect. “Community-Powered Motivation. Track your progress and cheer each other on.” Used mostly to track times on routes and compare them with other users.
Activity-focused (mountain biking, hiking, etc.). Assumes user wants to record/share their ride/walk/etc. (like Stava), mostly on routes others have traveled (hoping to beat best times?). Social aspect to the app. Free version has basic features, paid allows features like off-line use.
Primarily for long-distance hikers (AT, PCT, CDT, etc.). Trail info, including user-submitted updates (status of water sources, shelters, etc.). Some free maps, but generally you have to purchase maps for the areas you’re interested in visiting.