https://youtu.be/TXiwzf-UJhQ
I wasn't sure I could get the performance required from Flutter/Dart vs. native as a one hour ride generates well over a million data points from all of the sensor data. However, performance has been more than adequate and the single code base has streamlined development.
If you want to give it a try, below are links to the app stores.
https://play.google.com/store/apps/details?id=com.rlued.hangtime
https://apps.apple.com/us/app/mtb-hangtime/id1516615267