Muviz is a cool and free new Android application that puts a floating visualization of your music on the on-screen Android navigation bar. If you use a phone by companies like Samsung that don't have an on-screen navbar, you can still use Muviz, which will appear right above your hardware region.
Muviz does not require root, which is good news for the common Android user, and the app lights up even when you use apps that are not bound to music only: you can be watching YouTube videos and get audio visualizations, for instance, and Muviz will also work with media players like the popular MX Player.
Of course, you can customize the way the visualization will look like: from the color, shape and size, it's all subject to your taste, and you can even go deeper and create a custom look with the built-in Creator Tool. Check out the app at the screenshots and hit the link right below to try it out for yourself.