-Styles must be improved (full width for smartphones, selectable text for PGN...)
-Tooltip text should fade (even when mouse stay on it, especially for small screens)
-Checkered stage 2: switch button at reserve position.
-If a played disconnect right after opponent sent a move, it might be never received: secure this
+For animation, moves should contains "moving" and "fading" maybe...
+(But it's really just for Magnetic chess)
+setInterval "CRON" task in sockets.js to check connected clients
+(every 1hour maybe, or more)
+Button to show all pieces that can move (next to expert mode; change icons)
+Style (crazyhouse): ghost image of reserve pieces are initially translated