Mobile Device Speed Changer

For Android devices I recommend Music Speed Changer, which is free.  Its icon is shown below.  Search for it in Play Store.

Once again you can play slowly while learning and then gradually get up to concert speed, without change of pitch.  (in fact, you can also transcribe and change pitch independantly if you wish).

Since the Webmaster uses Android devices he has no idea what is available for Apple products.  Watch this space for further advice.