Easily my most used addon, ever. Never gets new features, but it's fine since the real magic is its ability to highlight and notate any website, anywhere on the web, at any time.

Thankfully Diigo hasn't bloated it with junk or telemetry like other companies do, nor have they stripped out functionality like other companies do (cough Google cough).

The reason for 2-stars: the latest update (v6.0.0.5resigned1) has broken this addon. Once fixed, it's easily a 5-star addon. Til then, I had to uninstall and reinstall an older version in order for it to be usable again.