https://tilemap.town/index
Collaborative map building and chat
tilemaptown
https://unity.com/how-to/optimize-performance-2d-games-unity-tilemap
Create 2D levels quickly and boost the performance of your mobile game with Unity Tilemap.
optimize performancegamesunitytilemap
https://80.lv/articles/quickly-create-3d-tiles-by-drawing-with-this-unity-level-editor
Bekkoloco's tool will soon be available on the Unity Asset Store.
lightweightdrawingbasedtilemapeditor