Stock Android Music App with embedded lyrics support ( Lyrics3v2 & ID3v2 )
The lyrics (if available) will be displayed in 'Track Name' field.

Now supports external LRC or TXT file (file name must be same as the song).

Tap on 'Track Name' field to view full lyrics!.
Use checkbox to enable/disable Auto-Scroll.
Press Menu -> More -> Settings - for text size and color options
Press Menu -> More -> Share - to share music file
You can also set Ringtones

Note: Make sure the lyrics is stored in UTF-8 encoding.