Doesn't meet my needs because of the 1920×1200 maximum size. I was trying to work out why my custom size, which I need because I'm designing for phone screens, wasn't working. When I saved 1080×2160, a fairly modest phone resolution, there was no error message; it just didn't resize when I selected from the menu. Documentation of this restriction is buried deep in the FAQ https://mybrowseraddon.com/window-resizer.html so I wasted some time trying to work out what was broken.
This tool would be much more useful if this arbitrary restriction were removed. It would also be very helpful to be able to specify the size of the viewport, not just the window.
