Putt Line Pro - Green Reader app for iPhone and iPad
Measures the slope of the green then tells you exactly where to aim.
Putt Line Pro uses the iPhones built in sensors to measure the slope of the green. It then calculates where to aim by using the most complete known physics model of a putt. It takes into account the initial skidding, the rolling curve, and the final speed decay.
Tip: Find your green speed by hitting an 8-foot sidehill putt. If your putt finishes below the hole, then increase the green speed setting.
Limitations:
2.5 - 25.0 Feet
0% - 9% Slope