Use the link in the last lesson to get your own copy of the Stop Motion Animation app. Test it out. If you do not know what a button does, press it and see. You will find the ability to add photos, use green screen, add sound, import pictures and video content from outside sources, utilize green/blue screen, edit the video content timeline, etc.
Please have fun while exploring all of the apps functionality and the multitude of things it can do which are not listed above.
Also, while exploring the app, explore the many ways to create a stand (tri-pod) for your camera in order to hold the shot steady.