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.
You may consider adding first your form to your Facebook Fan Page if you have not done it yet. Use this guide: http://www.jotform.com/help/123-Adding-forms-to-Facebook-Facebook-Developer-Method-
JotForm has already been optimized for mobile views. Form works just fine on iPhones and Smartphones. Fields can be filled easily and they just fit properly on mobile devices.
Considering forms that are embedded of Facebook there can be a problem with displaying forms on mobile. Problem is related to the Facebook itself. You may check the following thread on Stackoverflow:
Hope this will help. Let us know if you need further assistance.