It seems like such as simple task, but there doesn't seem to be an APP designed just to wake up the D3. We can turn OFF the screen, but not back on unless there is something else going on at the time (music or phone call.)
Perhaps you should contact the developer for Just Shake and see if he can add "just wake up" as an option.
I never thought of it before, but I would also like to "wake up" my D3 with just a shake.
Good luck and keep us posted if you find something.