1. Forced registration. Unless you’re a service I trust and I’m accustomed to using, why do you make me register before I know what I’m getting into? Getting a download is hard enough. Don’t raise the bar even higher by forcing another action before a user can interact with—and find value in—your app.
2. Complicated navigation. Part of the advantage of using an app (versus a mobile site) is the ability to deliver targeted content at the touch of an icon. While we recommend everyone adhere to the “Three Click Rule” of usability, it’s even better if you can deliver in one or two. And it’s just as important to give your users an easy way to navigate back to previous pages—no one likes getting lost three pages deep.
3. Preference amnesia. Now that we’re a population of app-savvy users, our expectations have changed. If I’ve entered information about myself and my preferences, I expect my app to be “smart” about it. Leverage the data I’ve provided before to serve up relevant recommendations or information.
4. Long forms. Nothing is more annoying than trying to pick through registration forms with your thumbs. Limit forms to the minimum fields required, and use shorter alternatives where possible, such as a ZIP code instead of city and state. Wherever possible display default values, like today’s date or nearby locations.
5. Ratings prompts. Once is understandable (if tastefully done), twice is annoying, three times is desperate. Don’t constantly ask me to rate your app—it’s getting in the way of enjoying your app.
For more on mobile app best practices, check out Mashable for my 5 Mistakes to Avoid when Creating Branded Apps.