[goda90]

What would sandboxing an app like Google Maps look like? There are definitely situations where a sub-par map app would be detrimental. Obviously it's going to send data to Google, but do I have to sign into an account or will it have some other way of identifying my phone if I used a one-off account just for it?

[tranq_cassowary]

Google Maps is sandboxed even on the stock Pixel OS. Sandboxing is part of the AOSP. GrapheneOS hardens the sandbox a bit, but it's not the most significant feature of the project. What isn't sandboxed on Android OSes that license Google Mobile Services (GMS) is Google Play (Play Store, Play Services and for older installs also Play Services Framework). On GrapheneOS Google Play is sandboxed as well, so it's treated as any other regular app, it's doesn't get priviliged exceptions.

Sandboxing isn't what would prevent an app from sending data. Sandboxing restricts what an app can access on your device because access is gated behind permissions and apps also can't peek into other apps. So it won't just be able to grab and send out data you don't give it access to, which is the most important of course.

You can install Google Maps and use a dedicated Google account for it with limited personal info. You can avoid giving your real name and also giving a phone number if you make your Google account from within the app and on a trusted network (not a VPN adress but public WiFi or cellular). It won't be able to identify your phone using hardware identifiers because non-system apps don't have access to those, the only regular app that might be able to acces such hardware identifiers is an app which is set as the default SMS app. See: https://grapheneos.org/faq#hardware-identifiers

[dlcarrier]

It doesn't need to be logged on to a Google account, and it supports locally storing map data and generating routes, so you could turn on network access, download local maps, block network access, then use it for navigation without it calling home.

[goda90]

There's also value in live traffic and road closure information.