As indicated on their FAQ, you can upload your own csv word file with the following columns: word;weight;color;angle;font;url. My example looks like this:
Select a shape or define your own
You can choose a shape as you like, or upload a picture and configure by youself.
Fonts, colors, and layout
Can configure in your own way. For the colors, you can either add random colors or select a platte and add.
You can download your word cloud image to a PNG file (quality is OK) without any registration required. But I recommend to register because you can also export a json file to use on your own webpage.
Here is my word cloud in a schisto shape!