No. You're not required to use the app. You're not even entitled to use the app. If you want to use the app, you have to play by their rules. Plenty of device manufacturers have chosen to only offer iOS apps. No one talked about mandating that apps were available on competing platforms.

If you choose to use something like GrapheneOS, you are signing up for the fact that almost no one will test on your platform and plenty of things will be broken.

The app worked until a few weeks ago. GrapheneOS does not miss any functionality (nor security) for the app to work. The only change is that they started blocking non-GMS Android through the thoroughly anti-competitive Play Integrity.

Hypothetically, if GrapheneOS wanted to become a certified Android, it would probably not be blocked on technical reasons, only that becoming certified (last time a contract was leaked) requires running privileged Google Play Services (which is less secure) and pre-installing a bunch of Google apps that should not be uninstallable.

How is that not anti-competitive?

The issue here is not that they didn't test on alternative distributions of Android, the issue is that they went out of their way to prevent anything but the officially blessed distributions.

The basis of your argument, that users want these developers to support another platform, does not make sense, because GrapheneOS does not require apps add explicit support for it. GrapheneOS has 99% android app compatibility.

The issue is not that this application isnt tested on GOS, its that an anticompetitive, illegal tool is being used to ban non-certified OSs when these apps would work perfectly otherwise.

Here it is, the true hacker mentality.

This is one of the most ignorant comment I ever read on Hacker News. Are you from VW?

Obviously VW broke the app for GrapheneOS (or any other custom ROM) on purpose, and ironically, things usually works fine for custom ROMs than some Chinese OEM customized ROMs, and when it works, it means the developer went extra miles to implement workaround to cater the flawed OS.[1]

[1]: ref: Years of Android community experience

The difference here is that the devs specifically chose to stop allowing the app to work on the OS without any known compatibility issue? The app just works fine on Android should they let it run.

Increasingly these kinds of apps are a requirement for a lot of features so ...

Sure the app is not required, though one loses on all of the remote-control functionality (remote start, remote climate control, etc.).

Maybe then app developers should be mandated to open fully their server-side protocols, so people can create apps for platforms that are not supported by default. No more undocumented APIs, anybody can get an API key, no API serving limits!

"tEsT yOuR PlatTfORM"

Fuck that.