We are all comfortable with the RIA (Rich Internet Application) concept in the desktop web and Web 2.0, but we can also create mobile RIAs. Some of the techniques used are the same, and others are not: while all the Ajax pieces (strictly about network requests) are the same, some UI and richness controls need to be redesigned for the mobile world.
A mobile RIA is also called webapp, a term often used to define iPhone web applications that emulate the native UI behavior and can include offline work and home screen icon support.
Problems with the devices, including lack of a big screen and lack of mouse support (and the various kinds of mouse events), have made mobile RIA development more tricky than we might have hoped. However, the richness in services (e.g., autosave mechanisms for large text inputs) can be developed in the same way regardless of whether the application is targeting desktop or mobile users.
Some UI design pattern concepts that work great in mobile RIAs include:
For other concepts we need to think twice and ponder alternative solutions. Implementing the following can be more complex:
Drop-down calendars for non-touch devices
CSS modal pop-ups
Flash-based interactions and menus