Plucky outdoor enthusiasts prefer to hike the old-fashioned way: a map, compass and self-reliance. Others may need a digital guide to help them on their way.

Wikiloc (Android/iOS, free + IAP)
An online community of outdoor enthusiasts sharing millions of outdoor trails around the world for hiking, cycling and outdoor activities. Members share details of new trails on the app including location, distance and difficulty rating. GPS works in offline mode for every trail, so you'll remain on the right path even in areas of poor connectivity. Be warned, it can drain battery life quickly so pack a portable charger.
SpyGlass (Android/iOS $5.99)
One of the most visually impressive apps out there, it's packed with all sorts of clever tools like binoculars, a hi-tech compass with offline maps, gyrocompass, speedometer, sun, moon and star finder, sextant, and inclinometer to name just a few (phew!). It saves custom places and waypoints, and using real-time augmented reality displays detailed GPS information.

Seek (Android/iOS, free)
Is that poison ivy over there? Can I eat those berries? Seek helps users identify plants, animals, bugs and fungi simply by taking a photo and uploading it to the database. It's designed for naturalists but if you've resided in a concrete jungle for so long that you can't tell your morels from your lion's mane (species of wild mushrooms, who knew?) it'll come in handy. Also try Tree Book.
Chimani (Android/iOS, free)
This app is like having a guide in your pocket. Curated by real-life guides, it provides detailed maps of parks across North America, complete with useful tips including where to find nearby accommodation, the best sunrise, parking and more. It can be a little slow to load and some maps need updating but the idea behind it is sound.
AllTrails (Android/iOS, free + IAP)
With over 100,000 trails and maps, it's one of the most popular hiking apps across the United States and Canada. The free version allows you to create your own trails with GPS tracking, photos and text and share them with others, similar to Wikiloc. The premium version has extra functions such as offline routes, and the ability to design and print custom maps.
Gaia (Android/iOS, free + IAP)
Gaia offers a range of outdoor maps for free, allowing users to plan trips and record GPS. Backpackers and hardcore hikers might prefer to splash out for the premium version ($40 per year) which lets you download maps and specialised overlays which show private and public land, avalanche terrain (for backcountry skiers) and backroad maps.
Others: Charity Miles: For every mile you walk, this app will donate money to approved charities including the ASPCA, Alzheimer's Association, Feeding America, the World Wildlife Fund and more. Recreation.gov: This app helps you find and reserve campsites and review location details for your trip. Weather Live: A detailed weather forecast is essential when deciding what hiking gear to take with you or what water-logged trail you'll need to avoid. Red Cross: Accidents happen and with this app, you'll find tips for common first aid scenarios.