There are many music player app which has a lot of function to help transcribing. mimiCopy is my favorite app to transcribe. This app is not that expensive compared with other similar famous app and this has good enough function to transcribe.
- Changing tempo between 25% and 200% with keeping good sound quality.
- Pitch shifting
- Loop playing
- Quick rewind (from 0.5s to 50s)
The official site mimiCopy
Check and Buy this app:mimiCopy in iTunes