(a) It is recommended that on mobile touch enabled devices common gestures be used wherever possible instead of on-screen controls. Compare and contrast both approaches and explain whether you agree with this statement or not. Finally support your argument with a real- world example.

(b) You are designing the UI for an Android application that will allow the user to select from a large number of possible actions. However, there is no time to get feedback from user interface testing. You have, therefore, been asked to come up with a suitable mechanism to determine which actions should be prioritized (and hence displayed more prominently in the UI) and which should be less visible. Describe a suitable mechanism to enable you to do this.

(c) Describe the roles of the back and up buttons in Android navigation, making sure to explain where their functionality differs.