Good luck with that when Apple offer the same thing for free on iOS.
And FLOSS on OsmAnd
I've found that OsmAnd's directions are high quality, but it's UX needs some more TLC. It's something I can use because I found poking around at it somehow enjoyable, but it's not something I can yet recommend to people who aren't peculiar in that sense.
I'm not saying they are perfect, but I installed it on my parents' phone and the learning curve is not that steep. They are perfectly usable by mere muggles.
OsmAnd is being developed at a steady pace, and the UX is being improved.