3 Ways to Disable Facebook Chat
How to Hide Your Facebook Online Status
3 Easy Tricks to Read Facebook Messages Without Seen 
Now, in terms of how KidsGuard Pro for Android can see Facebook messages without knowing, you can check the user guide below.
Now you just need to flip the "Show when you're active" switch to the off position.
Thanks Reply This was great however I can see when some people were active and the time stamp when they were last on, but cant see others.
The same goes for the web browser.
A filled-in blue circle means that the message has been delivered and a small profile picture of the receiver in the circle indicates that the message has been seen.
Hide Facebook Status with AdBlock Plus If you use a browser for most of your Facebook activity, there are a bunch of extensions you can use that can hide your online status.