Reviewed over a year ago here, Cartograph Maps Pro UWP is a top notch solution for anyone going off the beaten path, showing OpenStreetMap-based Mapsforge offline maps (which are popular among hikers, tour skiing, mountain-biking, and other outdoor activities). Here's news of a major new update, with changelog and screenshots!

From the developer:

After a long time I have uploaded a new version  (2.4.5) of the Cartograph Maps 2 app for Windows Phone 10 to the Microsoft Store. This update brings the Windows Phone/Store app to the same level as the app on other platforms (iOS, Android, macOS, Windows). 

Among many bug fixes and small improvements, the most important cross-platform additions which were missing in the Windows Phone version (and are now included) are:

• Online and offline "What's here" feature (reverse geo-lookup), including Google- and Bing Places.
• POI/Marker customization options (marker size, show/hide text label above marker).
• Support for Garmin waypoint symbols.
• The user interface is translated to: Dutch, English, French, German, Italian, Russian, Spanish, Traditional Chinese.
• Custom map coordinate projections (besides the standard WGS84 Mercator projection).
• Offline slope overlay map (useful for tour skiing for estimating a hillside's slope).
• Tools for measuring distances between points.
• Custom map popup commands.

The full change-log is available here: https://www.cartograph.eu/downloads/changelog.txt.

Different hiking trails; (right) a loaded route and its altitude profile

Offline slope map overlay (the more blueish the color the steeper); (right) Live display of "Watersupply.at" drinking water sources.

You can grab this (or the update) in the Store here.