This is a solution when you are required to make sure your visitor has to agree to your terms or whatever before they submit a form, but in a "sly like a fox" kinda of way. It's unique in the fact that unlike a lightbox solution or "I agree" checkbox solution, the visitor has already taken the time to fill out the form. That means, they are committed to the process. It works great in short and long form, but it shines on the long form or multi-step. I use it and my form completion conversion has bumped 10% in many cases.
Note: It uses the Sweet Alerts 2 script as it's main backbone of functionality.
For a step by step on how to and the actual scripts involved -> Go Here
To skip all that and see an example -> Go Here
I hope that it comes in handy for the community