This is the best forms plugin I have found and still use. Beautiful looking forms and fully customisable. You can connect with Stripe and also setup up payment forms using this plugin. It also supports Zapier. Plus a lot more.
Give WordPress donation plugin
A slick and customisable donation plugin for WordPress with various add-ons and modules.
ConvertKit blog user tracking
ConvertKit is the best e-mail service for bloggers, website builders, and Shopify store owners. You need a ConvertKit account to use this plugin. The plugin helps customise content on a website for the visitor, and also tags the user in ConvertKit when visited.