The Repper, it sounds cool and it is cool, great for art class. I used it for my Information technology classes to make a background picture. The company that made this tool just started out. There is no registration, but that means there is no room for you to save. In order to save from this program, you have to download it. And careful how you download. The program downloads with no ending name. In other words, it does download a jpegbut make sure the ending (jpg) is listed at the end. It just calls it picture you need to change the name. This program is still under construction and they are asking for suggestions to fix it up.
So here is what you do. You can upload a picture (there is a size limitation - poor quality picture off the internet work best, but not one of your pictures from a camera), or you can choose one randomly in the program already. By moving the square around you can change the pattern. By going to the middle lines you can make the square bigger or smaller, changing the patterns. You go to the corners to make the square larger, and by going to the center and click and drag you can move the square anywhere on the picture.
When you want to save you can save, get the html coding to insert that in your web site or use the CSS code to change things. You do have your options and it does seem to be made for web designing. But just playing with this program was entertaining, seeing what angles and moves does what to your background.
Have fun, it's not a difficult program to learn, students picked it up very quickly, and I had to talk to them about background colors and getting a background that was not too busy, or dark. This program took 30 minutes of the students time to create three different backgrounds. Here are some instructions.