
Description: Pencil Project is a free and open source GUI prototyping and mockup tool. It allows users to create wireframes and prototypes for software interfaces and websites quickly and easily, without programming knowledge.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Mockingbird is a user-friendly web-based tool for creating mockups, wireframes, and prototypes. It allows designers and developers to quickly sketch out web and mobile application interfaces with simple drag-and-drop editing. Key features include reusable components, collaboration tools, linked mockups, and exporting visual assets.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API