DB Navigator for regional transport is hit-and-miss. I've been using it a lot around the southwest, but it's fickle and sometimes fails to offer me tickets for

DB Navigator for regional transport is hit-and-miss. I've been using it a lot around the southwest, but it's fickle and sometimes fails to offer me tickets for no clear reasons (seemingly at random; the same connections by the same companies work on other days). And don't forget that a lot of the German hinterlands has very spotty to no mobile data.