The TL;DR for this project is to stream the blockchain from one app so that other apps can subscribe only to the exact operations they want to know about.
I'm also converting a few of my other apps away from directly streaming the blockchain over to this approach. The upshot is that if I have 2 apps, each streaming the entire blockchain (~400GB/day), when using this approach, there's a single stream for those 2 apps.
https://steemit.com/utopian-io/@inertia/meeseeker-update-0-0-3pre1