Project Sandcastle has been discontinued. Similar apps include Android, which is free and open source. Other options are LineageOS, /e/, Ubuntu Touch and Replicant. There's no shortage of Operating Systems like Project Sandcastle, with more than 25 alternatives for Linux, Android, self-hosting and iPhone.
Open-source mobile OS developed by Google, based on the Linux kernel. It supports app development in Java and Kotlin. Compatible with various devices, offering seamless integration with Google services, customizable interface, and extensive app ecosystem for smartphones and tablets.
United States
Free and open-source Android-based operating system for smartphones and tablets, designed to enable deep customization, enhanced privacy controls, regular security updates, and broad device compatibility without default proprietary Google services.
United States
/e/ is a fork of LineageOS that aims to be completely free of everything Google. Not only that, but there are a number of goals the developer has in mind for /e/ that more people feel are vital to a mobile operating system.
France
EU
Ubuntu Touch is the Ubuntu operating system for mobile phones originally created by Canonical and now developed by the UBports Community.
GermanyEU
Replicant is a fully free Android distribution running on several devices, a free software mobile operating system putting the emphasis on freedom and privacy/security. It is based on LineageOS and replaces or avoids every proprietary component of the system, such as user-space...
United States
Plasma Mobile turns your phone into a fully open hacking device, just like a PC. You can join us to start building new mobile experiences now.
GermanyEU
Android-based OS emphasizing privacy, open source transparency, tracker and ad blocking, independent app installation, digital sovereignty, community development, routine updates, environmental sustainability, and a familiar interface for alternative Android devices.
FranceEU
iOS is a mobile operating system designed by Apple for its iPhone and iPad devices. It offers a user-friendly interface, intuitive features, and seamless integration with other Apple products. With iOS, you can access a wide range of apps, games, and multimedia content, as well...
United States
Mobian is a project to port the Debian Linux distribution running the mainline Linux kernel to smartphones and tablets.
alternative, open source version of Fairphone OS, built by Fairphone, that puts transparency and ownership in the spotlight.
Sailfish OS is a European alternative to dominating mobile operating systems, and the only mobile OS offering an exclusive licensing model for local implementations.
FinlandEU
Distributed microkernel OS with AI and edge computing capabilities for smartphones, wearables, TVs, tablets, and IoT; features multi-layered architecture, custom device kernels, Linux ABI compatibility, seamless interaction, and resource sharing across devices.
China
Netherlands
