The CORE app for Android and for iOS allows you to view live and historical core body temperature metrics, update firmware and pair a heart rate monitor (for sports use).
CORE on Garmin
Additional guidance on setting up the CORE Connect IQ app and data fields can be found here: Using a Garmin device with CORE.
CORE on Wahoo
The following guide documents the setup with Wahoo devices.
CORE on wearOS
The CORE wearOS App can be found and downloaded from the Google Play store
Additional guidance on installing and using the CORE wearOS app can be found here: Using the CORE wearOS App