tst-tab-count

This Firefox addon, a helper addon to the TreeStyleTab addon, displays the total count of tabs in the "new tab" button:

Install it from the releases page!

Developer

web-ext build --overwrite-dest

Go to about:debugging and load the addon from the web-ext-artifacts directory.

Publish

1. Increment the version in manifest.json
2. Commit and tag the release
3. web-ext build --overwrite-dest
4. Upload the zip file to the Firefox Addon Developer Hub
5. Download the signed xpi file and upload it to the GitHub release