Hoverwatch Mobile Tracker is the best app available to spy on Facebook Messenger for free. At no charge, this facebook messenger tracker app https://www.hoverwatch.com/facebook-spy-app enables monitors to view all incoming and outgoing Facebook messages as well as get the GPS location of a target phone.
If the users use photos, images or audio recordings in their conversations, all these files will be saved as well. They can be viewed in your user panel from any device with Internet connection. You can read all the messages, view the images, and even listen to the audios exchanged by the users