Hi bugsy7193! You can find the following answer in our FAQ:
Short answer: No.
Long answer: Most of the images displayed by the gesture tools have been provided on loan by very generous photographers, professional and amateur alike, who have an interest in training fine artist. In offering their images, many of them specified that they were to be for educational use within the tool itself, and not to be reused for any other purpose. That means that we have use rights for a very particular case, but do not own the commercial rights and thus cannot give you permission to use all of the images shown in the practice tools in work you plan to sell.
Most of our images link back to the original photographer’s website or portfolio in the top left of the tool. If you are interested in a particular image, you may want to consider following the link and contacting the photographer directly. Some will have the answer to this question posted prominently on their site.