Earphones/Power Cord Rollup Storage

I made this because I got tired of having my earphones and power cords getting tangled. All you do is open the ball, add the earphones/power cord to the middle and turn the halves for it to coil up inside. There is a lot of room for improvement. I am thinking about making the earphones version flat and adding a clip so that you can clip it to your shirt, sweater or pants for when you go out for a run or walk. Eventually, I will also like to add a spring so that instead of turning it by hand fo