Have a map with more details then online maps? Make a photo of it, calibrate* it (using openstreetmaps.org within the app), and use the location of your phone to navigate the map.
Works great with local travel maps, but can be combined with (drawn) maps like pirate maps as well.
(*Calibrating is unnecessary if you received the photo from someone who already calibrated it within the app, and shares it from the app.)

App uses service to receive locations while the app is not visible. In this way the app can animate from where you started the walk. Swipe the app away to stop the service; the app will save any maps you have already matched against a background (but you will lose your location history).
Watch the video to see the app in action.

Want to test new features? Features such as drawing on the map was first available in the open test version before it landed in the 'production' version.
(To participate: visit https://play.google.com/apps/testing/nl.vanderplank.navigateanymap ).
Latest feature in open test: Experimental version of exporting the map (pre-matched), the track, or both. If the last option is choosen, you can view and show the track you walked on the following website:
https://vanderplank.nl/navigateanymap/view_my_trails/
You will need to upload the exported map and trail (do not worry: these will not leave your device, but are used locally by your browser) and thus showcast your trail.