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.
Unfortunately it is not possible to convert a form into a downloadable app. Although you can still add the form to your phone's homescreen. Simply follow this guide to learn how: How to Add Websites to the Home Screen on Any Smartphone or Tablet.
If you want to create an app, I have found several website that can help you create an app:
Do let us know if you need further assistance.