Finally I found I was searching for.

Wow, this is fantastic. This has been the only thing that keeps drawing me back to Firefox. Something about my brain works better when it can see the overview of the tabs, and this is perfect. It's way more advanced than Safari's tab overview as well. Thank you very much.

Under the sucking framework of Webextensions of Firefox Quantum (57+), this extension has done a great job to find a workaround to display thumbnails of tabs in a fast a neat way.

Also very complete in features to manage tabs.

very useful and convenient

This extension convinced me to completely switch from Safari which has a similar feature out of the box.

Brilliant work, thank you!

This allows me to visually see which tabs I have open. I found the preview thumbnails to be too small, but they zoom with the page using the normal browser controls (CTRL+, CTRL-). The UI looks like something I would have made (i.e. not super beautiful), but it is perfectly functional! Thanks, William!

Grate for previewing when I open 100+ tabs. I suggest add a new feature to cache the thumbnails to ensure they will not become empty after re-opening the firefox.

I'm quite happy to have found this as a replacement of the Showcase addon, that was so practical under FF39. If you tend to have a lot of Tabs open, this is the way to quickly overview and sort them.
Thanks so much for coding this!

Great job. Works great on linux. Thanks! Small feature request: a dark mode?

Удивительно, что у данного расширения пока так мало пользователей - ведь это по сути единственное пока расширение для нового файерфокса, заменяющее прежнее расширение Showcase, позволявшее выводить список открытых вкладок с миниатюрами - очень удобно для визуального поиска нужных вкладок, когда их открыто множество. Это вообще расширение, которое должно быть у всех, и, надеюсь, что оно скоро наберёт намного больше пользователей.