It is no secret that kaleidoscopes are a lot of fun to play around with. There are a ton of unique ones you can try. The Horizon Expander is a new kaleidoscope that lets you use your smartphone to take your experience to the next level. You can turn its knob at the end to use it like a regular kaleidoscope but this can also hold your phone.
Anything on your smartphone can be played through the kaleidoscope. You can also open your camera app to see the world through the scope. This project is getting funded on Kickstarter.