With the Spritesheet Cutter (also called Map Editor or Level Editor) you can cut/share/export/move/name single or multiple sprites using drag & drop. There is a copy mode so maps can be created. Sprites are numbered left to right/top to bottom or randomly. Sprites can be added to a sheet and saved as a whole. An animation preview is included. Spritesheet Cutter cannot create GIFs, but there are better solutions.
Color selections can be converted to transparency.