For sending a small amount of data such as URLs, IoT commands or encryption key are extremely common in IoT applications. Smartphones are used to transfer text commands to interact with IoT devices. This application uses ultrasound as a means of data transmission for proximity networking on commodity, consumer hardware. This application closely examines different modulation or demodulation schemes that are inaudible to humans and achieve a high data transfer rate. This application is designed a library to run well on low- powered devices, and provide a socket-like interface for easy deployment. This helps protect users from various attacks improving the security of our system.