Flinto!

Lucidchart is an online diagram and flowchart software that supports Microsoft Office Visio import and can work on any operating system. The easiest way to draw flowcharts, wireframes, UML diagrams, network diagrams, mind maps, iPhone mockups, site maps and more. Work together in real time with your team and clients! Along with the online version, Lucidchart also has a downloadable solution that runs on Mac, Windows and Linux; this enables offline editing at any time! »

Lucidchart is an online diagram and flowchart software that supports Microsoft Office Visio import and can work on any operating system. The easiest way to draw flowcharts, wireframes, UML diagrams, network diagrams, mind maps, iPhone mockups, site maps and more. Work together in real time with your team and clients! Along with the online version, Lucidchart also has a downloadable solution that runs on Mac, Windows and Linux; this enables offline editing at any time! »

InVision's prototype tool lets you create interactive wireframes and high-fidelity prototypes. Share your work and get instant feedback right on-screen.

Using Balsamiq Mockups feels like you are drawing, but its digital, so you can tweak and rearrange controls easily, and the end result is much cleaner. Teams can come up with a design and iterate over it in real-time in the course of a meeting.

Figma is the collaborative interface design tool. Keep the team focused and on the same page with real-time communication and collaboration featuring commercial quality vector and raster graphic tools.

Prototype mobile interactions as easy as Pie.Compose elaborate interactions and animations easily, and build sensor-aided prototypes without a line of code.

Axure RP is the leading tool for rapidly creating wireframes, prototypes and specifications for applications and web sites.

Framer combines the power of code with the ease of visual editing. Prototype beautiful microinteractions or realistic apps. It’s time to design with development in mind.

Principle makes it easy to create animated and interactive user interface designs. Whether you're designing the flow of a multi-screen app, or new interactions and animations, Principle lets you create designs that look and feel amazing.

Cacoo is a user-friendly online diagramming tool that allows you to create a variety of diagrams such as wireframes, flowcharts, UML diagrams, network diagrams, mindmaps, sitemaps, database diagrams, and more.

Free web and mobile mockup tool.Transform your design and mockups into clickable interactive applications. Perfect way to validate ideas faster with lean startup thinking.

"Go from idea to prototype faster with Experience Design CC (Beta), the first all-in-one cross-platform tool for designing and prototyping websites and mobile apps. Test-drive the beta and watch the video to see how we’re evolving XD to bring you exciting new ways to collaborate and deliver a whole new experience in user experience." - Adobe.com

Origami Studio is a free design tool built by Facebook designers for creating interactive UI prototypes. An elegant, layer-based interface allows designers to repaidly create prototypes with layers, build interactions and then share them with others.

UXPin is a web-based system for managing design documents like wireframes, sitemaps, persona descriptions or flowcharts. It lets you upload image files, invite teammates to review and comment on them, and keep track of revisions. The system also includes its own wireframe editor that supports real-time collaboration and allows you to export your wireframes to HTML. Another feature worth noting is that UXPin can convert paper prototypes into digital wireframes as long as they have been created using an official UXPin notepad (available for $30 on their website). You simply take a picture of the prototype and it will automatically be recognized by the UXPin app. Prices for UXPin start at $7 per month for a single-user project. »

Fluid UI is the fastest mobile app prototyping tool available. Design and test your low and high fidelity app mockups on a mobile device with ease. Simple and UX oriented, this UI tool helps unlock creativity and will save your team time and money while gathering app requirements.