Developed by the Ohio Supercomputer Center (OSC) and funded by the National Science Foundation, Open OnDemand (openondemand.org) is an open-source portal that enables web-based access to HPC services. Clients manage files and jobs, create and share apps, run GUI applications and connect via SSH, all from any device with a web browser. Open OnDemand empowers students, researchers, and industry professionals with remote web access to supercomputers. From a client perspective, key features are that it requires zero installation (since it run entirely in a browser), is easy to use (via a simple interface), and is compatible with any device (even a mobile phone or tablet). From a system administrator perspective, key features are that it provides a low barrier to entry for users of all skill levels, is open source and has a large community behind it, and is configurable and flexible for user's unique needs. This tutorial is meant to provide attendees with the basic tools to allow them to develop or integrate new applications into Open OnDemand. Nearly any software application can be made accessible via OOD.