Justinmind - Define awesome experiences through wireframes & prototypes.
Marvel for iOS - Rapid design and prototyping for the iPhone and iPad
Live Sketchpad - Live collaboration app
Peetch - The last PowerPoint Pitchdeck you’ll ever need
UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
Keynotopia - Prototyping straight into Keynote or Powerpoint