While I do believe that killer apps have had their day for the foreseeable future, I can't deny that the unbundling technique can be used to create some great apps.

Ed Rex reckons there are three reasons why unbundling works. Couldn't agree more with his reason for simplicity.

When your app only needs to do one thing, it can do it really well. You can have big, clear buttons for the things people use it for — because there’s no need to clutter up the screen with all those other options you’ve got rid of. This makes your app unbelievably easy to use — and that’s what smartphone users want.

— The Formula For Creating The Next Killer App by Ed Rex

Read on for the full recipe.