Element

Element.io is a free, open-source, end-to-end encrypted messenger and collaboration app that uses the Matrix protocol. It's designed for group chats, remote working, and other collaborative features, and can be used for video conferencing, file sharing, and voice calls. Element.io is decentralized, allowing users to own and control their own data by self-hosting it or using a hosting service. It also integrates with other online tools, such as project management tools, VoIP services, and other team messaging apps.