Believe it or not, there are plenty of social networks and messaging apps that you can use instead of Facebook. For years these networks and apps have been living in the shadows of the mighty beast that is Facebook. But now is the time to explore a better way of interacting with friends and family without the fear of your data being stolen and stored on huge servers in far flung places.
One of Facebook's most useful features isn't the main app itself, but its spinoff app Messenger. But while Messenger makes it easy to chat with Facebook friends, it's also confusing and riddled with unnecessary clutter. If you're looking for a clean and easy-to-use messaging app, try Signal. It's a free, end-to-end encrypted messaging service, approved by security researchers, that sticks to the basics. There are no animated stickers or fancy chat bots, but Signal does an excellent job of keeping you securely connected to your friends and family.
“In the future, MeWe will also revolutionize social media with decentralization, which will render Facebook’s spying and tracking data model completely obsolete,” Weinstein added, a comment that suggests he is indeed trying to replace Facebook. “Awareness around the world has never been higher regarding news feed manipulation and privacy infractions. Government regulations will never truly interfere with Facebook’s data collection model, evidenced in both California’s new 2020 privacy rules and Europe’s GDPR. But the free market can — and MeWe is here giving people great communication technology in a true multi-feature platform, with none of Facebook’s BS.” (source)
A simple chat (slack style) it's enough. Just having the possibility to send messages either single user or team (#channel). But please don't forgive to give an useful appeal to mobile app (worst error of competitors is, have a good app but totally no mobile friendly!) i would expect to have a similar whatsapp or slack app for messaging within the slack mobile app!