Stripe Billing - A set of tools for billing and subscriptions
Survey Monkey - Create and publish online surveys in minutes, and view results graphically and in real time. SurveyMonkey provides free online questionnaire and survey software.
PayHere - Run a services business or startup? Charge recurring and one-off payments with beautifully designed payment forms. Get up and running in less than 5 minutes!
Typeform - Create beautiful, next-generation online forms with Typeform, the form & survey builder that makes asking questions easy & human on any device. Try it FREE!
Square Installments - An easy way to offer monthly payment plans to your customers
Google Forms - Simple web forms from Google.