I’m working on it! It’s really about interoperability. You probably know that, but everything is organized around that principle. Without it, each app would become its own wallet, with its seed, custody, identity and funds management.
HandCash has an SDK that got us part way there but it was all wired in to HandCash so every application was against their api. And now (as you know) HandCash is moving into that brc100 world.
I’m designing a bootcamp for it. I’ve done some videos on the primitives. For example I showed how you can have an app log into you with just your key in one vid. That is a core piece of brc100 for any interaction between user and app.