F1 : this help

F2 : config size

F3 : open file or ctrl+o
    

F7 or ctrl+s : save file
  save the map

F8 or ctrl+o : load file
  load a tileset for a new map or load a saved map
  the Tileset file must be in the same directory than the saved map

[ESC] : quit without saving

how to use :

start with map.py

Click on a the tileset to choose a tile, the left click on the map to draw the tile, right click to cover the entire map with the tile.

The tileset given is not in public domain, but found on the net. If you have a tileset under a free licence and want to add it to Yamm, feel free to send it to me.