This week we sell our skills in videos, slow down any song in Apple Music, make wild music with Factory, and more.

Perfect Tempo lets you speed up or slow down any song in Apple Music, so you can learn how to play it. Unlike every other app that does this, Perfect Tempo works on any song on the Apple Music service, not just purchased and/or downloaded songs. It also has a great, easy-to-use design, which is way better than the utilitarian drop-down lists of many other apps.