Best free android sat Nov turn by turn directions

andyh01

Hi all I'm looking to get off main roads and explore more off road routes. What's the best free app for navigating off road with turn by turn directions.mainly on tow paths and national cycling networks.
Ideally something that will warn if off course and reroute if off track.
I'm also starting a new job with new cycling route but not sure of way so again something to direct me.

Thanks Andy