With the emergence of Cyber Physical Systems (CPS), networked sensing and actuation are all around us. Yet current computer science and engineering education in K-12 do not typically cover them due to various barriers. However, one project which attempts to solve these problems is NetsBlox, which provides a block-based interface to allow students to write distributed programs in a way that abstracts away most of the underlying complexity while still allowing students to learn the most important concepts. We have created an open-source phone app called PhoneIoT that connects to NetsBlox and gives access to all of the sensors of the mobile device. Once connected, students are able to use the block-based NetsBlox environment to communicate with the device and retrieve live sensor data. The user interface on the phone can be also configured through the student’s NetsBlox project which, in turn, sends notifications that the students can process by writing event-handlers. The showcase will demonstrate a number of compelling applications of PhoneIoT, such as using the phone’s accelerometer to control a game running on the student’s computer by tilting the phone or to implement a compass.