CalyxOS (for mobile)

ClearOS Mobile (by ClearCellular)

Debian (A free and open-source Unix-like operating system)

/e/

GrapheneOS (for mobile)

LineageOS (Free and open-source OS for devices based on Android mobile system. This OS allows you to safely replace Google and Apple on Android type phones.)

Linux (Considered one of the best OS alternatives. Versions are available for almost any computing platform (super computers, desktops, chromebooks, etc…)

Plasma Mobile (Runs on Linux OS for Android)

PureOS (A free, secure, stable, and freedom/privacy respecting OS for pc and mobile devices. This OS allows you to escape from Microsoft’s, Apple’s, and Google’s control, spying, selling of info, etc….)

Purism (You can purchase their different products including: cell phone, SIM card, laptop, mini PC, servers, thumb drive, power banks, or cellular plan with the Pure OS.)

Qubes OS

Replicant (for Android)

Sailfish OS (for Android)

Tails (Its system is based on Linux OS. It routes all traffic through the Tor network.)

Ubuntu Touch (for Android)