I have found rectangle indispensable. In my particular setup my second screen is in a separate room from my main screen -- being able to send and properly place

I have found rectangle indispensable. In my particular setup my second screen is in a separate room from my main screen -- being able to send and properly place a window to the other screen in the other room is incredibly helpful. The shortcuts to quickly arrange screens without the need for a mouse is fantastic. Love rectangle.