
Description: Principle is an open-source visual tool for building interactive UIs. It allows designers and developers to design, prototype, animate and develop user interfaces without writing code. Principle focuses on animations and interactions.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: PreVue is a web and prototyping platform that allows users to create interactive prototypes and share them with others to gather feedback. It is useful for UX designers, developers, and product managers to visualize and validate product ideas.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API