What are some alternatives?
When comparing Yoast Plugins and ProntoForms, you can also consider the following products
Gravity Forms - Gravity Forms is one of the best and easiest contact form plugins to create modern forms for websites powered by widely-used WordPress.
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!
Wordfence - Comprehensive security plugin for WordPress.
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.
WP Rocket - WP Rocket offers a caching plugin for Wordpress.
Google Forms - Simple web forms from Google.