Turn Any Smartphone Into a 3D Hologram Projector
This is one of the coolest things I've seen on the internet in a while and according to the instructions on how to make a hologram 3D projector, it's really easy to do too.
First you have to cut up a CD jewel case. I have hundreds of those. Follow the instructions and it should be pretty hard to screw up. Once you have the CD case cut to the specifications you basically you tape the pieces together to make an upside down pyramid with four walls.
Then you set it down it in the middle of your screen, and play a special video that projects four different versions of an image. So each side of the pyramid reflects the same thing, and it looks like there's a hologram in the middle.
Once you have your hologram projector made, here is the link to the special video that will make your hologram come to life, good luck and have fun