Simpler than simple. If you design your Web app to be simple, you’re off to a good start. But remember that “simple for PC users” is still to complicated for cell phones. You need to simplify even further.
Imagine the minimum functionality that people need when they access your site from a mobile device. They check the most important items, make the simplest updates. Provide that minimum and nothing more.
On a small device, every little feature you add makes your app much harder to use.
Minimize, minimize, minimize. Cell phones have tiny screens, little bandwidth and nothing much in terms of CPU or RAM. If the page is too big, it will take forever to download and then crash the browser.
Keep pages as small as possible, minimize or avoid images. Show excerpts and summaries, sometimes even a title will do. If the full content is important, break it up to small chunks.
Watch what you say. Use the right content type, DOCTYPE and make sure the XHTML is valid. Cell phones can but don’t deal well with bad markup. Don’t use unnecessary attributes, or anything fancy. This is about using the service, not being impressed with your graphic design skills.
Accessible. With small screens text is often better than imaged. If in doubt, test it with Lynx. Use the accesskey attribute often: it powers the numeric keys. If you need a menu of options, show the accesskey next to each option. For a good example, check out GMail mobile.
Don’t use links unless necessary. Tag clouds are great if you have a 15″ screen and scroll wheel. But on a cell phone, you scroll through the links and one screenfull at a time. The more links you have, the harder the interface is.
Test it yourself. Build it, try it, and improve on it. The best testing tool you can get is last year’s cell phone, if you don’t have one, they’re dirt cheap on eBay. Forget about a multimedia converging device with the power of a small mainframe. A device that can impress your friends is not something your typical user will have.
Have fun. The best thing about building mobile apps in 2006 is that you don’t need a WAP gateway, you don’t need to license obscure technology or strike deals with carriers. You just setup a Web server, write a few pages and off you go.
Labnotes » Hand me the phone