What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
I'm afraid that at the moment it is not possible to download all the uploaded files by one click, however you can integrate your form with dropbox in order to get a copy of the uploaded files at your dropbox account then from your dropbox account you can download the whole submission folder containing several uploaded files.
If you still need a solution by using the JotForm form submission page, I can forward this request to our feature request list.