wow that is an old video... feels like it has been forever since I last saw an iPhone like that one in the video.
since you mentioned that you are new to development I would recommend with first starting to learn how to develop single view applications in iOS. these are the most basic and most common applications in iOS.
to start I would write different applications that implement each of the different screens demoed in that application saving the gun firing screen for last. when you finally get to the firing screen you will need to learn about audio playback, basic animations and then as well shake gestures (accelerometer).
There are some great resources to get you started on this site as well as others like
YouTube[
^] and educational video sites like
Udemy[
^].
Hope this helps.
Dennis