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, Facebook does not support Tabs on mobile, which is why you won't see the form when viewed on mobile.
A workaround you can do is to add a direct form link as a Contact Us button on your Facebook page.
Another alternative would be to embed the form with the 'Static HTML: iframe tabs' Tab App: Adding a form to Facebook (Custom iFrame App)
This app provides you with a special tab link for mobile devices.
Then, you can use that mobile Tab link as the Contact Us button link.
If you need any further assistance, please let us know.