I have created a 3D hologram pyramid for the smartphone. one of the easiest DIY which any one can try. all you have to need is a Cristal CD cover and cut it as per the distentions shown here. Fix it with a sellotape or quick-fix gum. Refer the attached images for a clear idea.
There are many videos available in the YouTube. search for “3d hologram pyramid videos” and play in your smartphone. better to watch in a dark room so that you can enjoy the visual effect