My brother Larry and I have found a distinct difference in sound quality as we record items using Pocket Recorder. Andy Roberts of Sweetmansystems had suggested and we have verified that the microphones in the iPhone 6 vs. the 6S are different and the 6S is a lot cleared. You can verify this by also recording with Voice memos and you'll get the same result. The iPhone 6 sound isn't bad its just not nearly as crystal clear as the 6S. I don't know what this app sounds like with the 7 and 7S yet, maybe I'll get a chance to hear it at CSUN.