WireframePro

WireframePro lets you draw and collaborate on user-interface mockups for websites and apps in less time.

Features

• Wireframe Editor - WireframePro provides a full featured drag-n-drop editor for drawing user interface mockups. It includes support for master pages, presentation mode, layers, auto-sizing of canvas, interactivity, and icons, to name a few.
• Components - It comes with numerous components for a wide variety of user interfaces. This includes Web, Bootstrap Library, iPhone, iPad, Android Phone, Apple Watch, Android Watch, forms, and annotations, with support for more categories on the way.
• Export - Wireframes can be exported to a wide variety of formats: Images, MS Word, Adobe PDF, and MS PowerPoint.
• Template Store - Within the editor, users can access 3rd-party templates using "MockStore". A growing library of templates are available in MockStore which are submitted by the MockFlow user community. All templates are available for free, and can be instantly imported into a project.
• Collaborate - WireframePro provides collaboration features such as real-time editing, annotated comments which is essential for wireframing as it helps in seamless communication of ideas.
• Sharing - WireframePro is built for teams. Projects can be shared privately with permissions - reviewer, editor, or admin; and can also be viewed publicly by generating a preview URL.

WireframePro can be used for free with limited use. Additional options can be found here.