Not local, but I’ve been using my withings scale for at least 5 years, and I sync the weights with its home assistant automation from the withings api, then plot the data on a custom health dashboard I made.
I’d love a local alternative, but regardless I haven’t had any problems with my setup.
Jellyfin is awesome (I use it with my shield TV), but the reason I found plex worth paying for is their audio companion plexamp, and its integration with carplay.
I tested a ton of different apps and services, and other then plex the only good carplay experience was from online only services like spotify or similar that come with hefty subscription fees. Internet auth does suck tho.