Design for a Mobile iPhone & iPad Audience
No matter which device you target in your designs, the first element to consider is your audience. When an audience is using an iPhone, you can safely assume that they’re mobile and quite likely on the move — they may even be lost on their way to find your location.
Although the iPad is more commonly used at home or in an office, the iPad is a mobile device, and iPad users, especially those with the 3G models, are increasingly carrying their devices around with them.
Keep in mind the following key issues as you design for an audience on the go:
The need for information is often urgent: Many people resort to the mobile web because they have to, because they’re lost or late, or because they can win a bar bet if they know who won the 1987 Super Bowl.
Screen real estate is limited: iPhone sites should be designed to fit on small screens, and designs for both devices should make it easy to find important information, like your address and a map to your location, quickly.
Users are often distracted: Having to navigate road or foot traffic while reading content on a screen is just one distraction that may compete for your users' attention.
3G connections may be affected by low bandwidth: Limit the size of images and text so that pages load quickly, even at slow connection speeds. Remember, even 3G devices often connect at much slower speeds, especially when people are on the move.
The interface has limitations: Links and other navigational options should be big and easy to click with a (fat) finger.
Processing power and memory are limited: Large files and scripts that require fast processors don’t execute efficiently over 3G or slower connections.
Factors like time and place affect user actions: Don’t forget that users’ actions are likely to be affected by their locations, the time of day, and even the weather (whether it’s raining, for example). Be sure to include location-specific information, such as maps and directions.