A Browser Screen Mask

Here’s the idea. Imagine you are working in a browser window in an open office and you do not want other people to see part of your screen, or you want to step away and feel you should cover the screen. Or maybe you are on a video call and do not want to show the entire browser window during screen sharing, but you do need to show part of it. Add a bookmark button to your browser’s bookmarks bar, and when you click it, a white or black square appears on the screen (click the square to switch colors). You can drag it around and resize it by pulling the lower-right corner. Clicking the button again hides the square. The square’s size is automatically saved for each site. Turn on the bookmarks bar (Ctrl/⌘+Shift+B). Drag this button Hide screen or right-click the bookmarks bar → “Add page.” Copy the button address and paste it into the URL field.

I would appreciate any feedback on the script presented here. If you liked it, please click the like button at the bottom of this page. Thank you!