Storyly - Bring superb stories to your app
Steller - Everyone has a story to tell. Tell yours with photos, videos, and text.
InAppStory - Engage your customers with Stories right from your app or mobile web product with InAppStory.
Startups Anonymous - Anonymously ask questions and share stories. AA for Startups
Zuck.js - JavaScript library that lets you add Stories everywhere
Yarn - Yarn is a package manager for your code.