Source (link to git-repo or to original if based on someone elses unmodified work): https://github.com/PeerioTechnologies/peerio-desktop
Quick and easy, with no SMS fees. Create rooms for dedicated groups or purposes: projects, departments, or planning the next party. Chat with your team, store and share files, all in one place. Encrypted from beginning to end, your data is protected from hackers, breaches and prying eyes.
NOTE: This is only to provide appimages, I am not the developer.