I just published version 1.3.0 of my VTube Studio Plugin, 'vts-heartrate'. It adds the following features:
💓 Fitbit support! Use a special Fitbit Companion app to link your devices!
💓 Intuitive Art Mesh selection! Point-and-click on meshes to tint from within VTube Studio!
For those who don't already know everything else this plugin does, though, the high-level overview is that it can feed heartrate data into VTube Studio as a tracking parameter, much in the same way a webcam feeds position data in as a tracking parameter! This allows you to have aspects of your character model change as you physically become more or less agitated. That can include things like having the model become flushed, accelerating the breathing animation, as well as more specialized, tailored things, depending on the model!