Pagemask от Mitsubachi

Every time you click the button a black box will appear on the page. You can then move the box by grabbing the middle, or resize via the edges and corners.

I must say, this is mostly useful to cover up portions of a live stream or video that may contain other things you don't want to see... but it works on most web pages.

Cover up:

• Streamer camera views both real and virtual
• TV shows or movies that may be shown in corners of streams
• Chat overlay in video
• Blinking or animated decorations
• Anything else you may be tired of seeing

There's nothing automatic about it, and some caveats apply:

• The boxes are drawn on the main page, so frames will make it seem to 'stay' in place while other parts of the page can scroll around or navigate
• The boxes are rendered with a z-index of 99999, so conceivably web pages could render elements above it, in practice I've never seen this happen
• Boxes are not saved, refreshing the page makes them go away
• There are no settings for shape or color or opacity
• There are no controls to remove a box, you can only move it out of the way or refresh to clear them all

If I get more than 3 users I'll start adding features... I'll set up an issue tracker where we can talk about it.