This is a sat nav application especially built for cyclists,which is built upon the route planning engine from cyclestreets. A really good bonus feature is that it has a nifty feature to show you close by bike shops. Very useful if you break down and need some help.
And best of all this is FREE on the android market.
Similar to Bike Hub, but not as smooth and no bike shop finder. This is also FREE!Bike Route Android market link
This basically turns your android phone into a state of the art cycle computer. It tracks where you cycle (or run or ski or just walk around) via GPS, then it will plot the path on a map and give you a whole load of stats , plus pretty graphs showing your elevation and speed over time. You can also send the maps you plot to google map.
Another great feature , it's FREE too:
Cycle Hire Widget
This shows you where your closest boris bike dock is and also tells you how many bikes are empty slots are available at that location. Very useful if you use boris bikes and are always running into the problem of not finding a bike, and when you do find one,when you're done you can't find an empty slot to drop it off.
Another FREE app.
Provides instruction on how to fix many common bike problems. Might help you out if you break down in the middle of nowhere and not sure what to do.
Available on the android market for £1.79