Trekarta is designed for hiking, cycling, geocaching, off-roading, boating and all other outdoor activities. It uses offline topo maps so you do not need to have internet connection. You can easily create places and share them to others. It lets you write the track of your journey, even in background, so you will never get lost and be able later see where you've been.
Offline maps
Trekarta uses OpenStreetMap based vector maps that are lightweight, offline and are constantly enhanced by contributors. Maps contain detailed topological data with elevation contours. Some map elements can be filtered out for cleaner look. Trekarta has built-in hillshades support.
Hiking
Special hiking activity mode emphasises paths and tracks on map. It visualizes path difficulty and visibility and displays hiking routes. It also displays special OSMC symbols that help you identify desired route.
Cycling
Cycling activity mode reveals bicycle infrastructure. It shows cycling routes and visualizes mountain biking track difficulty and visibility.
Skiing and skating
Skiing activity mode displays clean winter map with mostly all skiing activities: downhill, nordic, hiking and touring. As a bonus freestyle snow-boarding, skating and sleighing areas are displayed.
Off-road
Unpaved, dirt, winter and ice roads are specially visualized. 4wd only roads have specific marking. Fords are displayed on all roads, even primary.
Places
Places can be easily created within application. You can navigate to places and share them with others.
Tracks
Trekarta is designed to record tracks of your journey. Simply press a button when you start and press it once more when you finish. You can quit the application if you do not need to look at the map, the track will be recorded in the background.
Comments and Reviews
I want to find an open source alternative to all the proprietary navigation apps, and Trekarta seems like the only one that is anywhere close to the functionality of something like AllTrails. Yet Trekarta is still slow and hard to use compared to proprietary apps, and lacks AllTrails's public database of trails/routes.
The developer has obviously put a lot of work into it, so I may yet realize much more of its potential as I experiment with it. An instruction manual sure would help though.