Try to make a calendar app with only one text field. There is no way "one text field only" can be applied as a general rule, but just thinking about how you cou

Try to make a calendar app with only one text field. There is no way "one text field only" can be applied as a general rule, but just thinking about how you could apply it will (IMO) make your app better. What the apps listed above have done is simplified the interface to the bare minimum needed to accomplish the task. Sometimes, that requires 5 text fields, sometimes 1. The biggest value of a good user experience designer is in figuring out the minimal functionality for each step in the application and stringing those together in ways that make sense.