MockupTiger is described as 'Web based application that helps you to build fluid wireframes, mockups or prototypes for your next web application or desktop software' and is a Wireframing tool in the development category. There are more than 50 alternatives to MockupTiger for a variety of platforms, including Windows, Mac, Web-based, Linux and iPhone apps. The best MockupTiger alternative is LibreOffice - Draw, which is both free and Open Source. Other great apps like MockupTiger are Pencil Project, yEd Graph Editor, Dia and Freeplane.