I just replied to one of the responses to my iOS/Android market newsletter, and thought it was worth sharing, because it hooks into something I think more people should know about.

The question:

I wonder how consumer mindsets affect the expected polish of UI, related to how much they have spent on a device. For example, after you've determined that the demographic for your app is that of a more thrifty, utilitarian Android user, is it then okay to skimp on flashy animations and design, or do you still need to deliver a product that looks as great as it functions?

My reply:

The way I see it, the more necessary your app is, the more utilitarian (for example if it's an app for a company's internal use, and all employees are mandated to use it), the less you have to do on design.

Generally speaking, though, the better something looks, the more people will use it. I've heard of studies where they show people will spend more time messing with an app that looks nice than an ugly one -- in essence, they'll spend more time learning about something just so they can look at it more.

Using something that I learned from a very smart fellow by the name of Nir Eyal ( http://www.nirandfar.com/ ) -- if you really wanted to crank this up to 11, you can use some psych tricks. You can vary the design in pleasing ways (for example, varied transitions between screens), and since they're random, it will actually get a user hooked on the app quickly.

Unfortunately I don't think there's any way of precisely quantifying polish, so you have to go for a range. If you're going through a design phase, it's probably best to do some market research -- look at the apps that your target market regularly uses, and consider that to be a baseline for UI and UX stuff.

The fellow I mentioned, Nir Eyal, is someone that I think more people should be aware of.

If your ability to make money is tied to getting people to do something repeatedly (visiting a site; taking a specific action within an application), you owe it to yourself to read his writing. His approach to design isn't right for all applications, but the perspective is something that should be in your mental toolkit. He naturally tends to connect user actions with profit, and has a good understanding of the principles behind it -- a killer combination.

I really recommend spending 10 minutes on his site. You'll be hooked.