Where to create offline maps?

Question

Cartography

Good day!
Tell me on which service you can create your own travel map, namely:
1. Create a main map with the location of any objects (caves, mountains, etc.).
2. Based on the main map, create routes.
That is, if the list in paragraph 1 is updated, then changes in paragraph 2 should also be added.
thank!

Answer 1

www.sasgis.org
Offline app but works great. There are simply no analogues =)
Saves in any activity.