Touch interface is no longer a fresh new thing. However interaction designers and product designers are coming up with fun and captivating ways to employ it for interacting and manipulating things. SphereTones is a great example of this. It is certainly not the first or even in the first dozen touch interface music applications. But the way users tweak and alter different spheres is a nice playful interaction, which allows them to change the tempo and sound created by each sphere. Currently only available on the Android platform, you can get your hands on SphereTones over on Google Play.