Is there a global hot key to open the Dejumble window?
Yes, will a little bit of setup. Dejumble provides a Toggle Dejumble Window Mac Service. Using Mac’s services feature, you configure a custom hot key to open up Dejumble’s window. Go to your Mac’s System Preferences then select the Keyboard preference pane (under Hardware). Click on the Keyboard Shortcuts tab and in the right table, scroll down to the Toggle Dejumble Window row. Insure that the checkmark is checked, then to the right of that row double click then enter a custom shortcut. If the short cut does not work, you may need to try a different key combination.