Window Resizer is an addon that lets you easily re-size and re-position the current window to your desired values.
Simply open toolbar popup UI and click on the desired layout set (size & position). Once you click a layout, the window will be positioned and resized to the chosen layout. There are 20 predefined layouts available to choose from in the toolbar popup.
If you need a custom layout, please click on the - Add a new layout - button at the top left corner in popup UI. A new tab will be open with a custom design layout UI. Simply drag your desired size within the orange area, then click on the - Save - button to store the custom layout. The new layout will be added to the popup UI.
Note 1: icons within toolbar popup UI are draggable and the new order will be auto-saved to the memory.
Note 2: to report bugs, please fill the bug report form on the addon homepage (https://mybrowseraddon.com/window-resizer.html).