Nielsen Norman Group Report - Usability of Mobile Websites & Applications on iPad

Summary points from Usability of Mobile Websites & Applications.

• When developing iPad apps/sites assume that multiple users use the device. Not permanentlty signed on and may quickly forget the passwords. (how then to make switching easier)
• Many sites/apps use mobile content for their iPad with richer data on their main web site. However many users use iPad in the home as a replacement for their laptop and so can't access much of the rich data.
• Search refinement is harder on iPad - often the rich facet navigation etc is missing.
• The ideal target size for a button is 1cm x 1cm - no smaller
• Include a search box
• Users expect padding - the whole row should be clickable, not just the link.
• Users don’t know that something is touchable unless it looks so.
• Build affordances by making buttons look tappable and relevant to the task they accomplish. This means choosing the right icons and labels for those buttons or action links.
• If the app does not store any information that is sensitive (e.g., credit card), then the user should definitely be kept logged in.
• If you have a lot of content (such as product information) to display, use a separate page rather than a modal view.
• When using Swipe make sure it works across the whole screen (in headers, carousels... otherwise provide a specific button.
• Always include a back button and make sure it works on the homepage as well in a true back style.
• Carousels are not appropriate for long lists (for instance, for search results).
• Two-dimensional carousels make it harder for users to remember which items they had already visited.
• Make sure that the same navigation scheme is used in landscape and portrait orientations.
• Don't make your launch/splash screen complex.
• Focus on a single feature at the time. Present only those instructions that are necessary for the user to get started.
• Users shouldn’t be forced to make decisions about non-essential tasks.
• Magazines on iPad should contain a table of contents in the header which should go to a details ToC rather than cursory headlines.
• Do not use multiple navigation schemes in the same app.

You can get a copy at http://www.nngroup.com/reports/mobile/ipad/