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.
As I checked your form, you did not add mobile responsive widget to your form. When you add it to your form, it becomes fully responsive through all mobile devices. You can do it from the form element tab on the left panel as seen here.
Here is the result after I added this widget to cloned version of your form.
If you have further questions, please feel free to contact us.