Answer by αғsнιη for Snap window to corner

Install compizconfig-settings-manager. Search for "compiz" in the Unity Dash, or start with ccsm from the command-line.

sudo apt-get install compizconfig-settings-manager

This windows will open. Type grid in "Filter" box and from right pane select "Grid" option.

Then this window will open.

Just click on each button (point 1) and then into "Edit <Key name>" window, choose Grab key combination and press your alternative key, then click Ok and enjoy

But don't forget, read /!\ Warning /!\ and don't change nothing more!!