Wow, it really saved my day!!! No whistles at all but very useful.

The best addon I installed in a long time!
Simple and efficient!

Woww! close hundreds of tabs with keyword or domain just by typing it in that little box in a fraction of a second!
So useful!
Thanks a lot developer!
For people who complain and want to know how many tabs remaining just install a tab counter like this https://addons.vaultpit.io/en-US/firefox/addon/tab-counter-webext/or this https://addons.vaultpit.io/en-US/firefox/addon/tab-counter-wide/the later gives you also the position of the active tab
Anyway if you use so many tabs like me (before this add-on more than 1500) you should HAVE a tab counter.
Again, thanks a lot Mosab Ibrahim for this Power Close add-on's gem.