Double click top or bottom border to stretch window vertically
Feature summary
I'd like to be able to increase or decrease a window's size vertically up to/from the available space left on the screen.
How would you like it to work
When the mouse cursor is above any point on the top or bottom borders of a window, a double click (or with Shift+Super+Up) will make the window expand (when it's not already expanded) vertically, or contract (with Shift+Super+Down, when it's been expanded already) to its previous size.