Been using Piotnet Form Builder for a couple of weeks now. It’s easy to use, but very powerful. I recommend watching some of the tutorials on YouTube for a quick start on understanding it.
I went with the Pro version, but it has far more features than I have had time to try out so far. So far so good though.
I had a reason to contact support recently and they were responsive and polite while fixing the issues I raised. Overall, I highly recommend this form builder at the current unlimited, lifetime price.