Thank you thank you thank you!!
I often watch a bit of cricket in a smaller FF windows while doing other things and this extension keeps that window on top with just a click on the pin. I sooo missed the add-on, I am really glad you brought it back as extension!!
Keupke

Vasyl, thank you so, so much for stepping up once again. It's working great. Flawless, and so useful. I'm back in business! Can't thank you enough! Blessings for the holidays to you and yours.

Could you please explain to me how I get this add on to work with the new Firefox?

I have added the add-on but pressing the Always on Top button only opens a window containing this message:
You have to download native AOT application before using this extension (new mozilla policy)
Please download three files from here(github repository) and run install.bat

So I went and dowloaded all 3 files there
aot.exe.html
aot_manifest.json
install.bat.html

Neither launching the aot.exe not the install.bat does any good - could you please explain to me how the installation is done? If I run the install.bat I only get redirected to a github page.

So? what is in this aot.exe file? how can i trust it?

Only <10% of FF users are on Firefox Quantum. Why do I have to use additional exe if previous version of this extension worked fine in my Firefox? I really hate how developers with all this quantum hype train don't care about previous versions of FF. Guess I'll disable auto-updating for all the other addons to prevent similar situatuions

UPD: Ok, thanks, I did not know that version history actually exists on this platform.