Here is my story.  I spent decades hiking, backpacking, biking and kayaking GPSing and mapping stuff.    I created free trail maps for Garmin GPSs https://www.gpsfiledepot.com/maps/view/53  I also found and added data from agencies and other users provided me data.  But I have been frustrated with Garmin and not being able to get the maps on my phone.  Then I found OSMAnd and decided to go with it.  So I have been taking points and tracks from I  the maps I created and transferring to OSM.