
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: Balsamiq Wireframes is a rapid low-fidelity UI wireframing tool that allows designers to quickly mockup user interfaces for web and mobile apps. Its simple and intuitive drag-and-drop interface makes it easy to arrange pre-built UI components to map out the structure and layout of an app.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API