Amazing. They are the best app for hiking (Komoot might be nice for planning, but nobody has the paths mapped so well - middle of nowhere, north of Sweden, Georgia, Mauritius, everywhere ti had silly small paths mapped for me).
I hope they can also be an option in the city. I don't drive, but I need to check their public transport coverage, and accuracy of opening hours ‿
Honestly, most of their data outside of Czechia is just OpenStreetMaps, so you could use many other apps that are actually opensource: OsmAnd, Organic Maps, etc.
The thing for me about mapy is not that they have fantastic database but layout of their maps - it's one of a few easily readable maps out there and unfortunately, especially for biking/trekking. I've tried alternatives but they're miserable most of the time.