hey, there, you can check this website for more info. www.nav4all.com also, i have heard tomtom is doing well too. it is wise to compare these two, and get the more compatible one for yourself.

 

I am using nav4all now for several months. It works fine and it doesnt use that much energy. It is free till august, so if you want to experiment with it just download it from their website. You can then decide self whether you like it or not.