[gumby]

By not doing so they are by definition non-compliant.

Or they could have GPLed the entire app; no reason not to have.

[MaxBarraclough]

> By not doing so they are by definition non-compliant.

Pedantry. If you agree a separate licence and are no longer bound by the terms of the GPL, you cannot be in breach of the GPL. That's the point.

> they could have GPLed the entire app; no reason not to have.

They haven't released the source.