Idea is great but...

I suspect the actual maximum detectable speed on a 5s is about 70 mph. I placed it exactly in the best recommended spot with no movement in the background and it only detected 4 slow second serves between 65-69mph. It didnt pick up any of the many faster serves and even some slower experimental serves. I would say detection rate is about 10% and I have no way to test accuracy as I have no reference radar to compare to but it seems strange all detected balls were within 5mph range.
Ill have to play with it some more try placing the phone higher maybe and closer or farther from the trajectory of the ball but for now I can only give it 2 stars in the hopes that it will develop into something useful.

Frustratating about Athla Velocity