While pro race drivers are used to telemetry-based feedback, us civilians don't have such an easy solution for our track days. BMW wants to take the guesswork out of those amateur racing sessions by launching its M Power app for iOS. The tool pairs an iPhone with a BMW Connected car to collect not just lap times, but the moment-by-moment input — if you're braking too late at turn three, you'll know. Drivers can compare their results, and it's possible to build custom tracks for autocross weekends. M Power won't be available until the summer, but it will be free to use for any Connected vehicle, whether or not it carries an M badge.