I bought the pro version of this product and loved it, until I started getting hundreds of spam submissions each day. It is now useless.
After letting the developers know, I was told to purchase the math question captcha. I was not given a price, or a link. I told them I didn't feel I should have to purchase another product to make the original product I purchased work. They should update their product so users can utilize anti-spam measures that actually work.
So, this product is great, but you will eventually get spammed and then it becomes useless.