Works as expected but it needs a button for the main bar Rated 5 out of 5 stars

It work as it should but it's cumbersome to go to the add-ons manager every time you want to enable or disable the feature.

lando Rated 5 out of 5 stars

Awesome

Exactly what I needed Rated 5 out of 5 stars

Although this cannot work on your smartphone or pad, it is still an excellent way to read your private messages through firefox and still keep privacy. Thanks for it!

Rated 1 out of 5 stars

Worthless. The last active timestamp is still visible to anyone using iphone and viewing messages you shared. So weather you read their message or not they still know you were logged in and are avoiding them.

Rated 4 out of 5 stars

How can I switch it off?

good Rated 4 out of 5 stars

works fine, but not like the Chrome's one..
the in-off button is not easily accessible, as the user needs to take a tour to addons sector, so that to enable or disable it.. a little more work gonna make this addon perfect

Great, can be imrpoved Rated 4 out of 5 stars

Does exactly what it's supposed to, blocks the read receipts.

However, as other users mentioned, it will list the messages as unread until you open the Inbox. It would be nice if there were a button that could be used to enable/disable the feature.

Rated 3 out of 5 stars

PROS:
- Does the job it's supposed to do.

CONS:
- No "on the fly" button to turn it on/off like in the Google Chrome version.
- Works by blocking the facebook php script which sends the "seen" notification. Problem is that same script also marks the messages as "read". This means that all new messages will forever be marked as "unread" as long as this add-on is enabled (thus, lack of on/off button is a real problem).

A better alternative is to use this user-script for Greasemonkey/Scriptish:
https://github.com/ldiqual/facebook-read-status-disabler/raw/master/facebook-read-status-disabler.user.js

That way you can easily turn it on/off on the fly!

Nice Rated 4 out of 5 stars

It works nicely. However, it would be better if users can put its icon on the add-on bar, so that they don't need to click a lot each time enabling or disabling it. Hope that this feature will be provided in later versions.

Good extension, but can be improved Rated 3 out of 5 stars

It's a good extension, but it would be even better if you could choose whether to see or not to see about every single message.
It is a shame it can not work with groups, but this not depends on the developer.

At first promising.. Rated 3 out of 5 stars

It does it's job in terms of facebook chat and to an extent the facebook messaging system. People won't be able to tell when you open a message or receive a remark on chat. Which is what it says on the tin.

However, it's got its issues. From time to time, it not only blocks other people from knowing you've read their message, but assumes you also haven't read it - so the message is marked as unread.

Doesn't work on messages Rated 2 out of 5 stars

The idea is good but I can't make it work with messages (aka when offline). Didn't test on chat. Firefox 14.0.1 on Linux.

Rated 3 out of 5 stars

It works on the Facebook message/chat correctly, but it doesn't work yet for Groups. Such a pity...
I'll be looking forward to new improvements to this extension.

Unfortunately, it can't be made to work with groups because of the way Facebook tracks your seen status.
It appears that it does it at the server side so there's no way we can intercept the tracking request.

Very good idea! Rated 5 out of 5 stars

Works good on the facebook-chat.
I'd like to know, whether this Add-On also works on the "seen"-Status in Groups. Anyway, I am testing and awaiting other comments of users. Thank you for this Add-On!
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Funktioniert gut im Facebook-Chat: die "gesehen um..."-Meldung ist weg.
Jetzt will ich nur noch wissen, ob es in Gruppen auch funktioniert. Bitte Erfahrungen hier posten!

Unfortunately it doesn't and can't work on groups because of a technical issue.