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.
Tippy.js - lightweight, pure JavaScript tooltip library
DO_Snapshot - command-line snapshot maker for your DigitalOcean droplets.
MetaBase is the easy, open source way for everyone in your company to ask questions and learn from data.
MailHog - Web and API based SMTP testing, inspired by MailCatcher
Localstack - a fully functional local AWS cloud stack. Develop and test your cloud apps offline!