In options it says it requires Container Tabs and says to Disable it even though Container Tabs are actually Enabled. Not sure if this means it no longer works.

Great addon. You can do this yourself by blocking a certain URL/announce etc at router/filter level but this makes it much simpler for people. Does exactly as described and blocks the report of you seeing message upon entering the message. However be warned as soon as you start typing it will update as seen so if you start but decide not to answer they will still know you have read message so only start if you're ready/available etc.

Excited

Tested and legit. Works exactly as advertised.

I like this product because I sometimes check my work account on a day off but don't want people to know and expect instant response. Only problem is that as it stands right now, I cannot tell if it is turned off or on?!? I used to be able to tell visually, but now both states look the same. If I can figure how to get it to show the difference again, I'll rate even better.

Great addition. Just letting you know it still shows up as LEGACY in the Add-ons manager.

How does this work, I don't understand what I have to do. Could someone explain please, TIA

Still works with the latest version of Firefox (49.0.2).
I am using it in combination with the AdBlock filter and it's perfect.
Keep up the good work guys!

Works as expected. It would be great if the facebook icon could be greyed when "disable facebook message seen" is unticked though

Trae un botoncito para activar y desactivar la función. No vaya a ser que se enteren que haces trampa.

testata

Добро е браво. :)

works perfectly, thank you !

finally privacy, a must

It does what it's meant to do and very well.