Tempo Changer App Design & Prototype

I use to LOVE playing around with music. Honestly I still would love to. I liked changing pitch to songs. There were certain songs I felt that sounded even cooler on different notes.

I can't be the only one that feels this way! They still make Audio pitch changers, but 1 they aren't free and 2 they only work on downloaded or bought music... How cool would it be to open an app that just takes up the phone in general?

Like an add on for other apps... How cool would it be to just open this app, then just go on Spotify and listen to your playlist with the pitch or tempo you set it at?

Let me know what you think of this!