CalyxOS

CalyxOS is a privacy-focused mobile operating system. The project provides a de-Googled version of Android, which replaces Google Play services with microG, and uses the F-Droid and Aurora software centres in place of Google's Play store. CalyxOS also optionally installs privacy protecting utilities such as a firewall which can block or filter applications, the Tor browser, the K-9 mail client, and Signal for secure messaging and calls.