I use RWGPS all the time to navigate on my Samsung S7 (Android). I usually download a route I create or download a route from an organized ride (if that's what I'm doing).

It works extremely well, gives true turn by turn directions (both visual on the map as well as spoken) and you can leave your phone in airplane mode and it will still work well with the GPS signal. It notifies you of upcoming turns well before they happen.......again 1/4 mile prior......and again just before it's time to turn and will name the street or road. Additionally it's all clearly displayed on the map.

All this being said it does require more than the free basic subscription. It's well worth it if you do long rides in unfamiliar areas.