Upscribe - Embeddable lead generation forms for Medium
Storyly - Bring superb stories to your app
Marvel Embeds - Embed interactive prototypes on any site (including Medium!)
InAppStory - Engage your customers with Stories right from your app or mobile web product with InAppStory.
Refined Medium - Chrome & Firefox extension that removes clutter on Medium
Zuck.js - JavaScript library that lets you add Stories everywhere