But I can make an RC car without it too. It’s a WiFi RC car. I too am curious who wants to modify a WiFi phone’s firmware and for what.

I also couldn't imagine what one was supposed to do with phone apps. The thought was: If functionality is useful just add it in hardware or to the OS?

I guess there will be awesome niche applications for this phone that are supper useful to an audience of one person.

You would still need a micro controller. It's easier to think of this as an arduino, that doubles as a phone.