Adobe XD is a commercial vector user experience design tool for designing web apps and mobile apps

Adobe Illustrator CC is a vector graphics editor developed and marketed by Adobe Systems.

Aviary Advanced Suite is a free suite of online creative applications, from graphic design to audio editing, which can be used right in the web browser.

Gravit Designer is a cross-platform, free design tool.

Moqups is a streamlined and intuitive web app that helps you create and collaborate on wireframes, mockups, diagrams and prototypes for any type of project.

Sketch is a proprietary vector graphics editor for Apple's macOS, developed by the Dutch company Bohemian Coding.

Adobe Fireworks (formerly Macromedia Fireworks) is a discontinued bitmap and vector graphics editor, which Adobe acquired in 2005.

Antetype is a design and layout software focused on visual design. It saves you a lot of time creating and optimizing UIs.

Balsamiq Mockups is a rapid wireframing tool that helps you Work Faster & Smarter.

InVision is a prototyping, collaboration & workflow platform.

Pencil Project is an open-source GUI prototyping tool.