Some usability guidelines for multitasking
- Users can work with more than one application simultaneously.
- An application can be left running and the user can select other applications from the application shell.
- It's also possible to swap two running applications.
- The number of different running applications should be limited only by the available memory in the device.
- User cannot launch a new instance of any application before terminating the existing one first. Selecting a running application from the application shell will simply revert to the existing one.