> If you run a libre device without the Google Play store (non-Google android build) then the software cannot function
I think you mean either of two things:
1. running the APK they build on a device without Google Service does not work
2. running the APK they build on a device means it's no longer running only libre software
1. is not true, so I assume you mean 2. I guess that's true, but in practice I think that the compiled dependency doesn't do anything if you don't have the services on your phone (don't quote me on that). It's not free software, but it's still better than the competition.
I think it sort of floats in 2 territory and sort of resembles the LGPL based kernel modules which require a binary firmware blob to run (kind of, not exactly). In order to create the APK, the code must compile against the SDK and encumber it by binding to an API, however if I understand this correctly in Android terms it means a stub of non-free code is now inside your APK, instead of say an external firmware blob. (I am not an Android coder to know the subtle details here)
(I'm aware that the code will try and use Google services, then if it fails it falls back to websocket(?) - so the actual Services don't have to be present, but the compiled APK contains the non-free hooks to use it if present? I tried to use the word encumbered to reflect that)
I think you mean either of two things:
1. running the APK they build on a device without Google Service does not work
2. running the APK they build on a device means it's no longer running only libre software
1. is not true, so I assume you mean 2. I guess that's true, but in practice I think that the compiled dependency doesn't do anything if you don't have the services on your phone (don't quote me on that). It's not free software, but it's still better than the competition.