I bet you don't know how much of a diamond in the rough this is. Initially put off by the pastel yellow and blue colour scheme, I was reminded of a Windows 3.1.1 interface (don't worry, you can change this), but the powerful functionality under the hood is both more powerful and reliable than Formidable Forms which charges a minimum of $80 a year.

These forms /calculators /spreadsheets can be embedded in your site, collect digital signatures and print PDF by default. They can collect payments too. All on top of having Excel type formulas on fields and conditional formatting. Plus it has near 400 templates to choose from or edit.
This is someone's labor of love and it quietly knocks the socks off of the competition that may not even know it exists.
5 tacos, I do recommend!