Greasy Fork

Pause/Mute HTML5 Audio/Video On Leaving Tab : Work perfectly !

Thanks :
It does that it said without problem :-)

Seems stopping to work ?
Test on Firefox Quantum

Still works when tested in YouTube with Firefox and Chromium.

Did you install a browser extension and/or other UserScript recently?

Sorry...
Now it work perfectly!
I don't know what was the problem before....
But maybe a mistake from me:
I test a migration from Waterfox Classic to Quantum and install many of mine favorits userscripts (your work in many place!).

Anyway thanks for your work :-)

Another Question:
It's possible with an userscript to have a button, in the browser taskbar, to toggle its action ?
Like certain addon have...
Should be useful for your script in think.

Unfortunately, it's not possible. Adding toolbar button require browser extension API which UserScripts don't have any access to.

By far, UserScripts can add menu items into Violent/Tampermonkey popup menu like shown in below screenshot.

Tampermonkey: the "Setting / ..." menu item of the "Popup Search" UserScript menu item.

https://user-images.githubusercontent.com/34861918/70062773-a1a68c80-1621-11ea-88d4-cb04191b5e4c.png

Violentmonkey: the menu items which have curly icon such as on "Change volume...", "Clear Spellcheck...", etc. menu items.

https://greasyfork.s3.us-east-2.amazonaws.com/zwcb000vw1vxs15ugs5yvzustcvc

Thanks for the clarification :-)