1. You can use your webcam, or you can upload a picture from your computer using the folder icon in the top left corner. 2. You can change size of the blocks using the SML icons in the top right corner. 3. You can draw on top of the canvas using the palette of colors down below. 4. When you're done, you can upload the result to Facebook if you want to.

The app uses getUserMedia and so it works best in Chrome as of now.

Enjoy!