Surprising App Design
It's good to get real with yourself in the fact that people see apps every day, and that making a bad first impression will lead to users immediately not using your app. The app needs to be able to function with 50% attention, and get straight to the point of the app. Like web-design, people just want to open the page, understand what's happening in less than 10 seconds, do what they know in order to navigate, and get out.
Technological Museums
Binding the worlds of analog and digital can be tough, but when pulled off correctly, can double your experience with any user. In order for the digital side to be effective, it needs to give the user something more than what they could have physically. With museums now using QR Codes, organizing apps, and digital studio tours, the experience within a museum has become more fuller. Users are able to now see what the see in the museum, but if interested, can view more photos, text, and video through their digital device.
Icons
Icons must always be perceived immediately. This is always improved with a similar design approach amongst every icon, including scale, color, and style. Even though the standard set of Apple icons may not be what you wanted, it's what works. If you're trying to compete with them you're going to have a tough time. Skilled designers spent a lot of time making sure the people have a good understanding of navigation through any apps created.
Gestures
Like icons, staying as close to the standard Apple gestures is always a good decision. Making sure the gesture feels right and that the gesture isn't taking away from the app is always something to do as well. The more natural and comfortable the user is, the more they will enjoy your app, it's that simple.