I have V-Navi installed only for a few days on my Galaxy S3 Samsug and even a few times used. The cards are not fully up to date, they recognize in my case, no, existing since 1 1/2 years building sites and roundabouts, but quite Tuen their service. Personally, I find it in the user interface but still better than Google Maps, which is currently just as little in traffic situations. Therefore, the V-Navi is free and of me, and my wife is used only sporadically in the second car, it is to use well. Additional information, such as petrol stations, attractions along the route, hotels etc. I do not need this "Zweitnavi". It must me navigate from A to B, and it does.