I use a bike with a powermeter on mine, so don't need to use the turbo derived power, however the calibration is a simple spin down which you can trigger from the iPhone app.
Having a trainer that displays power is a good way to cross reference different power meters. I was tempted to buy the watt box for my Lemond so I can do such. I used my rollers in the end.
I use a bike with a powermeter on mine, so don't need to use the turbo derived power, however the calibration is a simple spin down which you can trigger from the iPhone app.