The features that work are nice Rated 3 out of 5 stars

The panel itself works nicely and always shows the Facebook Messenger as it should.

Since the panel replaces the Bookmarks/History panel (which I'd like keep), you cannot change its position; it's always on the left hand side, contrary to what the description says.

Also, the "Open As Popup Window" option doesn't work - it just shows an empty popup, no matter how often I try, even after restarting Firefox.

This makes the plugin useless for me, although part of it works nicely.

Want side selection option!!! Rated 4 out of 5 stars

Please keep an option to choose the place where the messenger is to show(eg. right side, left side).

Works great Rated 5 out of 5 stars

Pervect!

This review is for a previous version of the add-on (45.1). 

Brilliant!! Rated 5 out of 5 stars

Brilliant

This review is for a previous version of the add-on (45.1). 

facebook Rated 5 out of 5 stars

ok

This review is for a previous version of the add-on (45.1). 

Works great Rated 5 out of 5 stars

Just a click to open and close, but I would like to be able to undock it from FF window, to have it as a separate window.

This review is for a previous version of the add-on (45.0). 

Works Great ! Rated 5 out of 5 stars

Amazing add-on so cool beautiful best of course I love it Thanks !

This review is for a previous version of the add-on (42.4). 

Rated 5 out of 5 stars

Now Its very easy to Chat with friends and Audio Video Calls through Facebook messenger its is Very Usefull application

This review is for a previous version of the add-on (41.1). 

Perfect! Rated 5 out of 5 stars

Works beautifully. Only thing missing is the archive chat function, but I think that's probably because of the way Facebook works. :) Thanks a ton, dev!

This review is for a previous version of the add-on (38.4). 

How to complement this add-on using Stylish Rated 5 out of 5 stars

Since I already reviewed this add-on as very-very useful, I would like to share that there are some scripts along with "Stylish" add-on that can complement this add-on.

In order to hide the contacts list completely and show on mouse-over:
https://userstyles.org/styles/112567/facebook-messanger-nice-tidy-and-more-responsive

Just to show the images of the contacts (and also show on mouse-over):
https://userstyles.org/styles/116878/compact-facebook-messenger
(and yes, this is by me)

This review is for a previous version of the add-on (38.4).  This user has a previous review of this add-on.

Rated 5 out of 5 stars

very usefull

This review is for a previous version of the add-on (38.4). 

Excelent add on, useful and good looking Rated 5 out of 5 stars

just what iwas looking for. now i can chat without the need of being on facebook all the time!
just one thing is missing, the option of hide the list of friends :(

This review is for a previous version of the add-on (38.2-signed). 

Rated 5 out of 5 stars

Muito bom! :D . Muito melhor o Firefox com esse complemento :D.
Obrigado.
Português - Brasil.

This review is for a previous version of the add-on (35.2.1-signed). 

Exclent add-on Rated 5 out of 5 stars

Exceptional work :-)
Thank you

This review is for a previous version of the add-on (33.0.1-signed). 

Rated 5 out of 5 stars

bon

This review is for a previous version of the add-on (2.1.1-signed). 

Rated 5 out of 5 stars

Very very very useful.
I stay on Firefox only for this addon.
If other browers have similiar counterparts, I will walk away.

This review is for a previous version of the add-on (2.0.1-signed). 

Rated 5 out of 5 stars

indispensabel hoy en dia y siempre

This review is for a previous version of the add-on (2.0.1-signed).  This user has a previous review of this add-on.

It works pretty fine Rated 5 out of 5 stars

This Facebook Messenger App is working better than Original. I have nothing to complain about, It`s just great and useful. The best part of all is that I can chat at any window of the browser

This review is for a previous version of the add-on (2.0.1-signed). 

Rated 5 out of 5 stars

This app runs as native Facebook Web messenger, thank to app's developer

This review is for a previous version of the add-on (2.0.1-signed). 

It is working Rated 5 out of 5 stars

El programa empezó a funcionar!!!! excelente!!! tengo las notificaciones y los mensajes en el box. Gracias! Excelente trabajo.The add start to working well. Excelente!! I have the notifications and de box chat, Excelent!! Thanks for this work. MI FF is 20.0

This review is for a previous version of the add-on (2.0.1-signed).  This user has a previous review of this add-on.