Audipo is a music player that can change music speed.  
The app is useful for music dictation, music practice, dance lesson, language study , and listening to long audio  etc.
You could use this app as audiobook player and as radio player.

Features
- Audio speed change. ( x0.25 - x4.0 )
 * This apps can change audio speed without pitch shifting.
- Advanced audio control designed for long audio track.
 Multiple seek bars provides more control of seeking long audio.
- Marking feature in audio track.
You could put marks on anywhere in audio track. You can play the audio from the position where you marked repeatedly. And the mark can be named.

The following features are unlocked by upgrading to Pro version.(It isn't free. In app purchase. Pro version is available for Android 4.0 or newer).
 - Widgets
 - Export audio tracks to wav/mp3 file
 - Pitch shift control( Swipe left in speed settings dialog to show pitch shift control view )
 - Playing playlist
 - Search songs / albums / artists
 - Shuffle play
 - Sleep timer
 - Remove ads

This music player is a good application for listening to a part of the music repeatedly . ( Ex. Music dictation. )
Also the app is good for listening the audio faster ( Ex. audiobook,  radio ) or slower( Ex. language study ).

*Required permissions
'Storage' is required to export audio to storage.