This activity should be about to display the last photo taken.

In photo preview activity should be able to add image effects.

A surface or texture view should be responsive to camera hardware's aspect ratio.

Preview in camera activity, user should be able to tap on preview area to focus

after taking an image, this photo should be unique id & and save into a destined folder

This activity to be able to route to camera activity.

Able to preview camera input in a surface or texture view

In photo activity, there should be functionality to output this image through email or wifi transfer

In preview activity, user can move slider bar to adjust exposure.