Those of you who know a thing or two about science toys have probably seen a few cool ferrofluid toys in the past. Most of them require you to use a strong magnet for interaction. The LYIEW SEED Interactive Ferrofluid Toy lets you do that and more. It has a music reactive mode, in which the magnetic fluid inside dances to the beat of your music.
This gadget has 10 sensitivity levels. It has a removable ferrofluid container, so you can always replace it or experiment with your own magnetic fluid mixes. The LYIEW SEED is inspired by arcade machines. It has a joystick and buttons for changing light, mode, and other settings. You can use this next to your phone or speaker.[where to get it]