Do not waste $0.99 if it is for iPhone 4s

Absolute waste of money. I have tried it in totally quite locations, keeping it level, and other things that should have improved results, but no luck. The closest to the correct measurement was within 2ft and that was in a noisy environment. Others say it worked on older versions of the iPhone. I could be doing something incorrect, but I have not found the correct procedure to make it work on iPhone 4S.

SnowmanLouisianaSouth about Sonar Ruler, v1.0