I must say, I used both apps for a hike that I did yesterday in the Ruhrgebiet (Hiesfelderwald, north of Oberhausen in the direction of the Netherlands border). Really excellent, amazing detail, absolutely no question of any navigational errors. Because even the maps in the Rother Wanderführer are sometimes surprisingly inaccurate, especially in the placing of the red line. Kompass used to be much worse, a real nightmare with much time wasted en route with navigational errors. But they have overhauled their guides and the new paths and depiction of the path ways (according to quality from tarmac to mountain trail) are really excellent.

Out of the two apps I used, I had a slight preference for the Alpenvereinaktiv over the Open Street Map one, but both were really good and a huge help when I came to dubious intersections on very small trails in the forest.