[Techno]

What exactly are these skins for? What program uses them, and what does the program do?

Is the only thing you do is ask questions? Like holy shit.
1.) These skins are for aesthetic value.
2.) The program that uses it is a game called Osu!.
3.) Its a rhythm matching game that you play by clicking or in my case tapping circles in rhythm to songs.
Some google would have helpt before you asked questions.