There is a new application available for Sparkers: Caprine.
What is Caprine?
Elegant Facebook Messenger desktop app.
Caprine is an unofficial and privacy focused Facebook Messenger app with many useful features.
Installation (64 bit only):
apt install caprine
The application is licensed under the MIT License.
The project’s GitHub repository: github.com/sindresorhus/caprine
The project developer is Sindre Sorhus.