The mobile app design isn't the same as web design. The most important thing an app designer needs to know is that the smartphone screen is tiny. Give users enough space to swipe or tap icons, but avoid cluttering the screen with information they can't see. The mobile UI design must focus on interactions and gestures, as the mobile UI is about simplicity and speed. The app design comes from understanding the difference between form and function. An app's function is its reason for existing — what it offers the user.
