I have long incorporated physics simulations in my physics teaching, and truly appreciate those who have made their simulations available to the public. I often would think of an idea for a simulation I would love to be able to use, but with no real programming background I did not know how I could make my own. That was the case until I discovered GeoGebra, which is an open source software offering "Dynamic Mathematics for Teaching and Learning." GeoGebra is freely available for non-commercial users. It is powerful, easy to learn, and versatile. There are versions for Windows, Mac, and Linux, as well as tablet and phone versions. It can also be run directly from a Chrome browser.