Practice reading greens with your phone as a level
Skitty Golf's Green Read Trainer turns your iPhone into a level so you can check your putting read on a practice green.
How it works
Make your read on a practice green: which way the putt breaks and how much. Then set the phone down and measure the slope. Skitty shows how your read compared with the measurement.
Why it helps
You find out whether you tend to over-read or under-read break, with a number instead of a guess. That's feedback you can't get from a missed putt alone.
What it doesn't do
It measures slope where the phone sits; it isn't a full green map or a putting line for your round.