This program is intended for quickly moving images from one folder to one of up to 9 other folders with only one keystroke per image (unless the destination has a file with the same name, in which case you need one additional keystroke). Subfolders are ignored.
You can open the program by simply double-clicking it, and you will be asked to browse for a source folder at the beginning. (Alternatively, you can pass in the path of that image directory or one of its files as the command line argument.) The folder you specify will have all its files enumerated immediately, so files that you add to the folder after this point will not be displayed without restarting the program. An image from that folder (not to exceed 50 MB) will appear momentarily.
F1 displays a brief version of this information.
Numpad 1 through 9: move the displayed image to a folder identified by the number pressed. The first time you use one of these keys, you will have to select a folder. Your selection will be saved upon exiting the program. You can change the destination folder for one of these keys by holding Control when you press it.
Numpad 0: delete the displayed image. (The deletion becomes permanent after you perform 3 more actions or when you exit the program.)
Enter: move the displayed image to the end of the queue. Use this if you can't immediately decide what to do with it.
Numpad minus: undo the last move or delete. You can undo 3 times.
Escape: exit the program.