What started a short list became quite a big description, more details inside the post.
Best Practices for Building a Microservice Architecture. Looks like a wide set of questions covered.
Waypoints is a JS library that makes it easy to execute a function whenever you scroll to an element.
snabbt.js - minimalistic animation library in JavaScript
Chartspree.io - kind a Lorem Ipsum charts. Allow to insert chart as image src.
Hover.css - a great collection of CSS3 powered hover effects to be applied to links, buttons, logos, SVG, featured images and so on.
Requestd gives you a URL that will collect requests made to it and let you inspect them in a human-friendly way