As I mentioned earlier..this is predicated on the user having installed a Mondo app. That is not workable.
You must have a flow where this works without your app being installed.
You must have a flow where this works without your app being installed.
If your flow is blocking on Mondo app being installed - that's fine. This means that the surface area of attack is restricted around your app. That's totally OK.
However - that is a very different positioning than oauth. I would say Oauth will degrade gracefully to your protocol if the endpoint is restricted to another app that must mandatorily be installed on the host device.