Keyboard shortcuts

Here are key/mouse combinations to perform quickly the most common operations.

(When there are two keys/mouse separated by a + sign, it means that you must hold down the first key, not release it and press the second key or button. Click means pressing a mouse button).

What to do	Key
Pick a piece	click
Turn a piece	(Depending on device availability) Turn mouse wheel  ←  or  →  Touch pad: Touch with two fingers and move
Resize the puzzle	I  (opens the resizing window)  Ctrl+←  /  Ctrl+→  resizes on the fly
Bring a piece that covers others to back	U
Nail a piece	Alt+Left click
Remove the pin of a piece	Alt+Right click
Hint on a piece	Ctrl+Alt+Left click
Switch Full Screen mode	F
View the image	Space
Solution Frame to position of the image	V  (while the image is visible)
Hide/Show Mini-Image	M
Show only the pieces of the edge	Ctrl+E
Show/hide the loupe	Z  or  Alt +click the desk
Select several pieces (with mouse over the screen or a tray)	click + drag
Scatter settings window	R
Scatter pieces protecting the solution frame (configurable)	Ctrl+R
Scatter pieces in the whole screen (configurable)	Alt+R
Save game as (set title, player and password)	Ctrl+S
Open/close the tray 1	1
Close all the trays	Q
Send a piece to the tray 1 (same for 2 to 6)	Alt+1
Send a piece from a tray to the main desk	Alt+Q
Open a puzzle from the gallery	enter
Access the gallery to open a puzzle	Ctrl+O
Game Info & Options	F2
Program Options	F3
Autosolve piece	F5
Change transparency of ghost image	Ctrl+G

Almost all these operations can be done through the menus and are shown in them as a reminder.