Entities can be created by clicking the plus icon in the upper left corner.
Similar to Tiles, the entity editor on the right allows you to change the texture of the entity with the same selector. Entities can be moved, resized, and rotated by using the handles directly in the editor. Entities can be duplicated, copied, and pasted.
Entities snap to the grid when moved and resized. The grid can be increased and decreased in size by using the plus and minus keys.
The background color of the editor, as well as the color of the grid, can be changed from the View menu. The File menu has New / Open / Save / Save As.