+1 for Cyclestreets - although it doesn't seem to give preference to cycleroutes, as you would think.
Copilot Sat-Nav app is free, as long as you don't want spoken directions - I paid the £20 unlock fee & now I get spoken directions through my bluetooth earpiece: Works a treat & has routing preferences, one of which is Bicycle! You can drag the suggested route on the map to go througfh any waypoints you want.