SonarPhone turns your smart phone or tablet into a fully functional sonar system that will rival any high end sonar on the market today. Using Patented WiFi signal technology to transmit to smart phones or tablets. You don't need cell phone coverage to use it, the SonarPhone will work anywhere in the world. The SonarPhone creates its own WiFi hotspot and you can share your signal with as many people as you wish, the software App is downloaded for free from the App store and works with both Android and IOS systems.