Gravity Forms is a WordPress plugin for advanced, embedded website forms. It integrates with popular apps and offers a set of addons.To integrate Stripe and PayPal you will have to pay a little over $250 (one-off price). According to top reviews, this price does not seem to put anyone off as you can create extremely personalised and complex forms, and choose when they appear (great for competitions and giveaways). Everyone loves the quality coding (this wasn’t the case a few years ago, but this plugin has undergone constant improvement). For WordPress websites, look no further.