
Description: Substack is an email newsletter platform that allows writers and publishers to easily create, design, and distribute email newsletters. It aims to let freelance writers and bloggers build direct relationships with readers.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Tumblr is a microblogging and social networking website that allows users to post text, images, videos, links, quotes, and audio to their tumblelog - a short-form blog. It has simple customization and is good for sharing creative content.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API