# Omni Omnigraffle + iOS Stencil (Paid): http://www.omnigroup.com/products/omnigraffle/
Get Stencils from: http://graffletopia.com/
# Sketch-kit Keynote Template: (Free) http://www.extrathought.com/sketchkit/
# Photoshop PSD Files (Free)
iPhone PSD: http://www.teehanlax.com/blog/iphone-gui-psd-v4/
iPad PSD: http://www.teehanlax.com/blog/ipad-gui-psd/
Other Options (Around 21 Different Tools): http://goo.gl/SwU2b
Summary: Use the tool you are most comfortable with. For example if you are familiar with Keynote then use Sketch-kit or other keynote templates. I personally prefer OmniGraffle. Best way to judge is: check the sample screens or video of these tools and choose the one you like the most.
