Want to train your dog, need to stop your neighbors dog from barking all night long? Then Dog Whistle Trainer is the application for you. Dog Whistle Trainer takes advantage of the iPhone/iPod's speakers to emit a high frequency sound that only dogs can hear. A custom slider allows you to tune the frequency to best meet your needs. Not all dogs react to the same frequency. As a result we have included 4 preset standards to allow you to never have to remember the right frequency. Put your dog on 1, and your neighbors dog on another and you can rapidly switch whistles back and forth to meet your needs.