How to mount smartphone on your putter

"Tired of endless putting drills? Let science help solve your putting woes!"
1. Hold iPhone4 in your hand, or mount it on your putter.
2. Start your putting for either a practice or a real putting.
3. Check Rhythm, Tempo, and Consistency Score.

‎'Putting Science' realizes all kinds of putting instruments by App. Not cheap but Inexpensive. Feeling+Science. From Tired to Fun