This project allows you to make your own animated GIF and export it outside of Scratch. Most of the instructions are given in the project. When you copied the text, go to http://www.motobit.com/util/base64-decoder-encoder.asp and paste it in the big textbox. Then chose "decode the data from a Base64 string (base64 decoding), and export to a binary file, filename, finally add a file name, it must end with gif, for example: supercoolimage.gif.
@-Jie- Now it clears the screen when you click the flag.