Rated 4 out of 5 stars

A simple extension that should get the job done for most people.

However, I use TabKit 2nd Edition to put my tabs on the side, the width shown on the toolbar only shows the width of the window instead of the width of the current document minus scrollbars (document.body.clientWidth).

The Alt+Left/Right window resizing shortcut keys are still useful though.

This review is for a previous version of the add-on (1.3.1-signed.1-signed).