TO THE DEVELOPER, THERE IS A BUG.
---When you have 914 tabs, among them pinned tabs, it shows the number 100 on the icon that represents this addon instead of 914. That ought to be a bug.
---When you have more than 1000 tabs, it shows 109 instead 1009.
---When it reaches 1,000 or more tabs, you could put instead >1k.

Very useful when you have many tabs open at each Firefox session like I do.
Thanks to the developer.