Hi,
I just came across this post whilst searching the internet, and its great that there's recent interest in this as I'm working on one right now as part of a university project.
You input mass of car & frontal area and find a flat stretch of road, accelerate to any speed (100 km/h is fine), begin to coast, press 'start' on the app. Coast down for a while then press 'stop'. The app uses the GPS to log your distance vs time curve, and interprets this to calculate the drag coefficient Cd and rolling resistance Rd.
I'm mostly done programming but now need to validate/test!
Do you think there would be interest in this app? how much do you think is a fair price for such an app?
