-
sfdx-flowdoc-plugin
A Salesforce CLI plugin that generates design document from Lightning Flow (currently Process Builder) metadata
-
SurveyJS
Open-Source JSON Form Builder to Create Dynamic Forms Right in Your App. With SurveyJS form UI libraries, you can build and style forms in a fully-integrated drag & drop form builder, render them in your JS app, and store form submission data in any backend, inc. PHP, ASP.NET Core, and Node.js.
I have not seen what you are asking for though in a ready-to-go app or UI , but I have seen Flow documenters a year or so back for process builder. Maybe it can get you on the right track if you decide to build something https://github.com/shunkosa/sfdx-flowdoc-plugin (note that I know this is for PB's, but the concept of Flow metadata and an output is what I wanted to show).