content: As far as I know, to submit an APK to Playstore you have to sign it with a certificate that has been "certified" by google when you signed up for the palystore You had to use a credit card, so, they have some kind of reasonable identity tied to the account. It is a simple chain of trust, all starting with Google, there is no reason why the cellphone cannot verify it without passing by playstore. In other words: The way it is done now gives Google a monopoly status AND there is no tecnology stop to do it correctly. In a way, we are saying the same thing, I am just adjusting your statement on "who is signing the app"