Good: ***
- It allows words to be grouped together and share the same highlight colour.
- When it comes to highlighting page, it is fast and not as buggy as some I have tried before.
Bad: ***
- Export function does not (never is more accurate) work (FF6x-FF71 or later, Kubuntu 18.10-19.04). Import probably broken too but it cannot be tested.
- Configurations (settings and keywords) are all gone if Firefox doesn't exit properly. Sometimes it's gone even when FF closes properly. You cannot do anything about it because the backup functions does not work. It happens ever
- Options drop-down from toolbar button have both H and V Scrollbars in lower res screen (e.g. 1366x768)
- No bug report available. Existing site acknowledge only chrome extension.

Brilliant extensions but too many bugs to be useful.

Been using this in Chrome for almost 3 years. And finally switched to Firefox. I love this tool!

*New update: May 14, 2019
Pastebin remote file sync do not work.

Works nice and adds a feature that I wish was natively in firefox.

Fantastic addon that I use for browsing through scientific literature (specific keywords). Earlier I used Phrase Highlighter but that is not working with Firefox quantum.