I've used navfree on android now for about 6 years as my standard sat nav app.
It's good, not had any issues other than a one way street which it thought was two way, next to the BBC building near to the station in Sheffield!
It works a treat, got heavy useage with obscure country addresses around Holmfirth when we were moving house, used in London, Leeds, Manchester, drives up to Scotland etc.
Would recommend it.