As you'll see in the video - once you launch the app you are prompted to scroll through a list of instructions. I realize that instructions can often be boring but with FaceJam they just look sweet, with nice clean images set on a white background with some blue thrown in for good measure.
The concept of FaceJam is to combine two, three or four photos onto one - kind of like a collage. So, it's just a case of selecting from the menu how many photos you want and then adding them to the spaces available on-screen. At the base of the display there is a tab which gives you quick access to switching between vertical and horizontal and once the photos are loaded into the app you can pinch to zoom as well giving as a long hold to reveal a further menu for rotating, flipping or adding another image.
Once you are happy with the finished product I'm afraid to say that there isn't a normal save option within the app, but as per the instructions you can just take a screen cap using the media buttons. The downside here is that when you go to view your creation within your pictures app there will be a small arrow icon at the base. I know that with the native photo editing tools it only takes a few seconds to crop and save, but it's a feature I'm hoping will be added in a future update.
Mind you, with the app being free and pretty darn good I can't really complain. If you are a Z10 owner check this one out and have fun.