Doesn't this also use its own app and services? The only "open" part of it I saw in the docs was that there's an sdk to write your own app that runs on the watc

Doesn't this also use its own app and services? The only "open" part of it I saw in the docs was that there's an sdk to write your own app that runs on the watch. Better than nothing, i guess, but not quite what I was hoping for.