People tend to put a lot of trust into their phones. Those devices have access to no end of sensitive data about our lives — our movements, finances, communications, and more — so phones belonging to even relatively low-profile people can be high-value targets. Android devices run free software, at least at some levels, so it should be possible to ensure that they are working in their owners' interests. Off-the-shelf Android installations tend to fall short of that goal. The GrapheneOS Android rebuild is an attempt to improve on that situation.