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.
Please refer to this guide: http://www.jotform.com/help/311-How-to-make-Forms-Mobile-Responsive.
Please make sure to enable this option in your Form Designer Tool
Also make sure to set the "Responsive Form" option in the "Preferences" to "Yes".
After applying those changes, make sure to click the save button. In the Preview using the Form Designer, this is how the image adjusts on a mobile view:
I hope that helps. Do let us know if this works.