Recipe to design Killer Applications

Back in the LTE world summit, I presented recipe for designing killer mobile applications. I have listed them out here but feel free to suggest some more things or to correct me.

Recipe to design killer applications:

• Something new everyday
• E.g., News
• Available instantly whenever needed
• E.g., Youtube or similar VOD services
• Challenging or Entertaining
• E.g., Games, Music, etc.
• Something that can reduce cost
• E.g., VoIP services like Skype
• Keeping in touch
• E.g., Facebook, MSN messenger, etc.
• Something to help in everyday life
• E.g.,GPS, Maps, LBS, etc.
• Purchase whatever and whenever you like
• E.g., E-bay or Amazon

You may notice that I have not listed Email and browsing above because they fit multiple categories. Can you add to the list?