JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
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.
If you would like make your form able to upload files to DropBox please take a look on this guide:
Also, if you would like to setup custom folders for your DropBox, you can use UniqueID widget. How it works, please check this link:
Please let me know if you have any additional question.
The guide provided by @cvelekv is the best way to integrate your form with Dropbox.
Please, do let us know if you need more help, we will be more than happy to assist you.