So as the title suggests, how about a map creator? Being able to create your own map would allow for the player to create his/her own scenarios. Furthermore, an in-game way to upload and download the maps would help people play on a certain kind of map without having to make it or search for map seeds. Also, if there was a map creator I think it should have an option to switch between a simplified mode and a more precise mode.
-Thanks for reading if you read to the end