TOP MOCK UP FLOW TOOLS

1. Proto

2.Moqups

3. UXPin

4. Balsamiq

5. Justinmind

6. Fluid

7. Axure

8. Mockflow

9. Wireframe

10. Omnigraffle

Omnigraffle is powerful wireframe and diagram application with a vast library of stencils to quickly mock up an iPhone app. Using the Pen Tool you can even create your own set of custom shapes or stencils. Layers are used to organize your project within the canvas -- if you're familiar with Adobe Photoshop or Illustrator, this will be familiar territory. Shared layers are especially useful for common elements, as they can be re-used across multiple canvases. As Omnigraffle is also a design tool, it includes features such as leading, kerning and margins.
It comes packed with a variety of templates and stencils, with others available from Graffletopia, including iPhone, iPad and Android stencils.