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.
You'll need to make the form mobile responsive. You can add mobile responsive widget in your form.
You are using the iFrame code on your page. The iframe code has hardcoded height so every time you make a change on your form, you must update the code. Or you can increase the height manually.
Try to increase the height and try it on your iPhone.
Hope this will help. Let us know if you need further assistance.