We have used this app in the US with very good results and will use it in EU in a few weeks. Its a bit complicated but certainly feature-rich. The simulator feature is handy for seeing what you will be getting into, especially in foreign countries. Having all the maps resident is essential. Well done.
Sept 24 update: we have used Sygic through Austria, Italy and Slovenia. There are two oddities to report: the first is that the program terminated as we crossed from Italy to Slovenia on the H5 road. It did this on both instances where we made this passage. I had to pull over and restart the app and it picked up and worked normally to destination. The second is occasionally upon initiating navigation, a message appears at the bottom left of the screen that declares "Inaccurate signal for car navigation". It will usually clear up shortly en route. Otherwise, even in the inner city of Florence, it took us right to the door of our hotel. Still well done and 99% reliable.
Mountainflyer about Sygic Europe - GPS Navigation, v13.1.3