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.
I believe we have, you can check the available signature related widgets that we have in this page: http://widgets.jotform.com/search/signature.
To add a widget, simply follow this guide: http://www.jotform.com/help/252-How-to-Add-a-Widget-to-your-Form
Do let us know if you need more information on this.