Extending well-built WordPress plugins and themes is something I do almost daily. Gravity Forms is a popular form-building plugin for WordPress that I integrate and customize quite frequently. Custom form fields, form settings, and third-party integrations are common requests.
Recently, I had to find a way to handle custom, dynamic redirects on form submission. The redirect would be dependent on query string parameters provided by an inbound affiliate link. I was able to quickly create a solution due, in no small part, to the fact that Gravity Forms is a “well-built” plugin.A "well-built" third-party plugin/theme means that it adheres to WordPress Coding Standards and makes APIs/hooks available to other developers for extending the base functionality, among other things.