OrchLab Soundmakers are a set of web-browser based instruments that you can use on a computer, tablet or mobile phone. The instruments available are called Circles, Squares, Percussion and Lines. Below you can find a video which introduces Circles to you. Feel free to use this as a starting point and then be as creative as you like with the different sounds!
An introduction to Circles
You can also find detailed written instructions along with further ideas for how to use the Soundmakers and what to play here.