Great tool that let's you manipulate fields (columns) and much more in Dynamics 365. Please only use it if you know what you're doing. Happy that it finally works again for Firefox. I now only have to use chrome for the impersonation feature and not for all other features.

Edit on 2023-05-08: The defect on github is updated and I can confirm it now works again on FF. Therefore I'm updating my review to the 5* that it deserves.

Original Review
I would honestly give it 5 stars if it was working. Sadly, it stopped working on Firefox for more than a month now. It is tracked on Github as issue #276, but I'm not sure when or if it will be resolved so I have to uninstall it for now. I will still be using the Chrome extension, but Chrome is not my main browser. I use FF as I use containers a lot and I log on to many different AAD domains for CRM.
If the bug is updated and this starts working again I'll happily change this to a 5 star review, the tool is really amazing. Until then, I'll have to live with Power Pane that still works.

(No longer working in Firefox as of March 2023.)

Just to clarify - this one star review is ONLY to bring attention to the fact that this extension is no longer working in Firefox (and hasn't for about a month as of writing this.) The tool itself is invaluable and deserves 5 stars, however it currently seems to only work in Chrome + Edge. No offense intended to the developer as he has created a great product; I'll be happy to remove or update this review if it resumes working.

Excellent app, been using for many years. Somehow stopped working this week. The button is just greyed out when I'm on a CRM tab.

Its a grear tool for Dyn365 Admins. Please, update to version 3.5.7 in Chrome and Firefox, its missing the Inpersonte function that rocks over other similar tools

Level UP is a terrific tool however after I install it in Firefox (84.0.2 (64-bit)) and restart the browser, he icon disappears :(