Super Slow Downer

Super Slow Downer allows you to slow the play of music while maintaining pitch.
Super Slow Downer allows you to play songs in a loop at a slower speed. It's great for musicians trying to learn new songs.
You can select any part of a song to repeat at normal speed. You can also slow the song down or even speed it up by changing the speed between 25% (0.25X) and 200% (2X speed). The pitch remains the same as you change speed. 
As an option, you can separately adjust the pitch in addition to the speed. If you want to change the key the song is in, you can do so in the app.
Setup loops by touching the "loop" button during playback.
You can load music files that are saved on your iCloud Drive or select music files on your device's music library (owned music appearing in the Music app). This app does not support Apple Music streaming music or Spotify streaming music.
Super Slow Downer is a great app musicians, music transcribers or dancers wanting a tool to make their practices better.