RAMBOX.-
Rambox is a free and open-source messaging and emailing application that aim to provide a central hub for managing multiple messaging and communication services in one place. It allows users to combine various messaging services like WhatsApp, Facebook Messenger, Slack, Gmail, and many others, into a single application.
Rambox aim to improve productivity by eliminating the need to have multiple messaging apps open simultaneously.
Users could receive notifications and interact with messages from different services all within the Rambox application. This was particularly useful for people who used multiple messaging platforms for work or personal communication.
You can visit the home page at .- https://rambox.app/ , there go to the FREE DOWNLOAD link and download the .deb archive (it is the easier to install in F96CE_XFCE_FUSILLI 4.4) , just click on it and install 
Download .deb .- https://rambox.app/download-linux/
Of course you can use all this "messengers" on line but for me it is really useful for my needs, so I wanna share this app for you.
Try it and post your comments if you like.-
Have a nice day.- CHEERS.- 