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 have tested your form in an iPhone emulator and I can see it displays properly, I have also tested in an Android device and I can see it works fine as well, here are some screenshots about it:
I can see you've already added the Mobile Responsive widget to your form and that you're using the default embed method, could you please try embedding the iFrame code of your form, here is the guide that will help you to get it: Getting-the-form-iFrame-code
Please do let us know how it goes.