First let's go with the inspiration:

Smashing "I love you" Magazine

Clearly, designing for the smart phone world is yet another mental model. There are a few keys to remember in successfully designing an mobile application:

Create a rock-solid informational architecture (IA). Make sure that the IA never goes more than three layers deep as a rule.
Solidify your thinking with a "Features and Function Martrix."
Keep the design simple and intuitive. Yes, I know this goes without saying but setting up the expectation to the user, no matter what they select, should be third-grade easy.
Make it BIG! Keep in ming that your navigation and call outs should not be subtle, delicate, tiny and fancy. This isn't sushi people, this is steak.
Don't make people sign up for anything. If you want repeat usage, you need to be smart enough to collect information deeper within you application or mobile optimized site.
Remember "sticky" well apps' are the new toilet paper – try em' and chuck em'. The only thing that's going to be compelling is freshness or content, modularity and or customization.
What do you do everyday? The best apps help to solve daily questions. Remember, if it can't help you stop and argument with your spouse it's probable not going to last long.
Prototype, test, focus testing, rinse and repeat. You get one shot in 100k apps to be good.
Don't try to be everything to everyone. There are so many apps out there better to do one thing great, an a lot of things mediocre.
Do to the amount of applications that are out, research your competition, end user, and feature landscape. Then reverse engineer the best attributes of their application and bury them on design, features and customization.

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