GF No Duplicates
Prevents duplicate Gravity Forms submissions when the same POST request data is sent more than once.
Gravity Forms already has some built-in duplicate submission prevention techniques, including the No Duplicates setting for a field in your form, preventing the same field value from being used multiple times for the same form. Using this setting is a rock solid approach to avoid duplicate submissions, but it requires having a field in your form that you can consider as a source of unique data per submission.
This add-on helps using the same idea, without requiring having a field to enable the No Duplicates setting, by dynamically adding a hidden input with a random token to the form, and checks the [POST request](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST) received for this token value to prevent duplicate submissions.
This would **stop identical POST requests** from being accepted for entry creation, like the ones that some browsers will send when the browser back or refresh buttons are clicked or when browser tabs are restored in mobile devices.
The page where the form is embedded must be **excluded from cache** (if you use any caching plugin or server cache).