How to spy on Facebook messages?

Anyone can read Facebook messages if they use spyware. This kind of apps guarantees that a person who’s spying won’t be caught. How is this possible? The developers anticipated spyware to run in a stealth mode and remain unobservable.
When spyware is installed on the target device, it records Facebook chats and their content. That way, a user can view messages, photos and videos, gifs and any other information shared via Facebook Messenger. The most reputable spy apps are iKeymonitor, Spyera, SpyHuman, Copy9, mSpy.