
Description: HotGloo is a user interface prototyping tool that allows designers and developers to rapidly create clickable prototypes and wireframes for web and mobile applications. It has a simple and intuitive drag-and-drop interface with various pre-built components and templates.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

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: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API