GrapheneOS is a privacy and security focused mobile OS with Android app compatibility developed as a non-profit open source project. It's focused on the research and development of privacy and security technology including substantial improvements to sandboxing, exploit mitigations and the permission model.
GrapheneOS improves the privacy and security of the OS from the bottom up. It deploys technologies to mitigate whole classes of vulnerabilities and make exploiting the most common sources of vulnerabilities substantially more difficult. It improves the security of both the OS and the apps running on it. The app sandbox and other security boundaries are fortified. GrapheneOS tries to avoid impacting the user experience with the privacy and security features. Ideally, the features can be designed so that they're always enabled with no impact on the user experience and no additional complexity like configuration options. It's not always feasible, and GrapheneOS does add various toggles for features like the Network permission, Sensors permission, restrictions when the device is locked (USB peripherals, camera, quick tiles), etc. along with more complex user-facing privacy and security features with their own UX.
GrapheneOS also develops various apps and services with a focus on privacy and security. Vanadium is a hardened variant of the Chromium browser and WebView specifically built for GrapheneOS. GrapheneOS also includes our minimal security-focused PDF Viewer, our hardware-based Auditor app / attestation service providing local and remote verification of devices, and the externally developed Seedvault encrypted backup which was initially developed for inclusion in GrapheneOS.
No Google apps or services
GrapheneOS will never include either Google Play services or another implementation of Google services like microG. See the FAQ section for more details on our plans for filling in the gaps from not shipping Play services and Google apps.
I am a big fan of GrapheneOS. If you want to do anything with your phone such as gaming, watching videos or using apps, the speed and stability of the system is a must. The only thing that I would like to see on it is some more customization options for the launcher. I prefer https://masterbundles.com/templates/presentations/powerpoint/colorful/ source to get free templates as they are quite good. I like how it looks now but sometimes when I reboot my phone, everything gets messed up because there are too many apps installed on my home screen.