Can you tell me which country Sygic is from and where to download it? Is it paid ?

For navigation, Google is very good. There's no need to download anything else. Local compatriots in London recommend Wezhi, saying it can remind you in real time of traffic congestion and adjust your route in time. However, I do not recommend driving in London city. Google can do it perfectly outside the city.

Bought for 30 yuan on Taobao, it will give you a main program and a map package. It's very useful, don't care about the network signal, especially there are obvious prompts for roundabouts.

If it's an iPhone, you can download the map directly in the app. You have to pay for the map download, but you can also make a one-time payment for unlimited downloads of all maps in the future.