Note that this "device" is not an actual oscilloscope. Most of the features you'd expect from an oscilloscope are not available. However, if you like to visualize data that is not too fast, then this is simply awesome. For example I will be using it to check a data sequence that I am going to create with a couple of 555 timers. But that is another story.
Features of the software/oscilloscope:
1-channel (original and fastest), 2-channel (slower), or 3-channel (even slower) data acquisition and display
0-5V signal range determined by hardware, i.e. Arduino
Time scale zoom in/out by pressing +/-
Red line = channel1 data
Green line = channel2 data
Blue line = channel3 data
Grey lines = 0.5V steps
Dark yellow lines = 1V steps
Screenshot functionality: On mouse button click the program stores a screen shot of your data window. This essentially allows you to "stop" the data and look at it. Convenient for data analysis. To make this work you have to go into the program "draw ()" section and adjust the file path to one that works with your computer.
All you need is an Arduino and a USB cable.