I love the idea of allowing anyone to build apps or experiences on top of some of these common elements. We have briefly discussed an approach where we make so

I love the idea of allowing anyone to build apps or experiences on top of some of these common elements. We have briefly discussed an approach where we make some of these common elements available as abstractions and let people build "apps" on top of it. It would operate kind of similar to how Google's app store does in that the head use cases (email, photos, camera, etc) are first-party apps, but then anyone can build and publish a third-party app using the Android SDK.