There is no need to signup to use Ethermap. Anyone from anywhere in the world can instantly start creating, viewing and sharing maps.
Ethermap has no adverts and never will have, it's just a financially sustainable service that is provided free-of-charge to improve the world. Also, without advertisements, there is also no need for Ethermap to track or store data about you.
Ethermap is free software. It is free to use for everyone and free to use for any purpose, including commercially. Ethermap is also free to share with others, free to study Ethermap's source code and even free to make your own versions and modifications.