I've made a small free app for Apple Watch and iPhone so you can see your hr info on the Karoo.
Be aware, it's still very much in beta. I made this originally for TrainerRoad, but I want it to work with Karoo as well. However, the Karoo is a bit more picky on the bluetooth connection (and Apple is of course a bit weird as well).
So, before testing, keep these two remarks in mind:
Alternative bluetooth mode seems to work better for Karoo (especially on pairing)
After first connect, when the status stays in "searching", disabling and re-enabling did the trick for me
You can download the app using this link: https://testflight.apple.com/join/M4IsgvXN
For questions and feedback, don't hesitate to send me a message on heartbyproxy@jorritposthuma.nl !
PS: If any Karoo dev's are reading, I'd love to send you some details on the Apple Bluetooth weirdness so I can scrap "alternative bluetooth mode" as a whole
