This release does not have a Play Store Description, so we grabbed one from version v3-build-809-play:

Poweramp is a powerful music player for Android.

Key Features:
- plays mp3, mp4/m4a (incl. alac), ogg, wma*, flac, wav, ape, wv, tta, mpc, aiff
- 10 band optimized graphical equalizer for all supported formats, presets, custom presets
- separate powerful Bass and Treble adjustment
- stereo eXpansion, mono mixing, balance
- crossfade
- gapless
- replay gain
- plays songs from folders and from own library
- dynamic queue
- lyrics support, including lyrics search via musiXmatch plugin
- embed and standalone .cue files support
- support for m3u, m3u8, pls, wpl playlists
- OpenGL based cover art animation
- downloads missing album art
- custom visual themes, lot of skins available on Play
- 4 widget types with many selectable styles, advanced customization; Android 4.2 lock screen widgets
- configurable lock screen
- headset support, automatic Resume on headset and/or BT connection (can be disabled in settings)
- scrobbling
- tag editor
- fast library scan
- high level of customization via settings

This version is 15 days full featured Trial. See Related Apps for Poweramp Full Version Unlocker or use Buy option in Poweramp settings to buy Full Version.

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Common Questions/Answers for Poweramp v2.x:
Q. Does my Poweramp v2 purchase include the next Poweramp v3?
A. Yes, it does.

Q. My songs are missing from folders/library.
A. Please ensure you have all your folders with music actually checked in Poweramp Settings => Folders and Library => Music Folders.
Your original Android Library is not changed, nor any files deleted.
Poweramp library is a separate, completely independent library. When you installed Poweramp 2.0, it just got filled with the files scanned from your sd card/other flash memory, as specified in Music Folders.

Q. Volume too low. Volume changes weirdly. Other volume issues.
A. Try to disable Direct Volume Control in Poweramp Settings => Audio => Advanced Tweaks.

Poweramp 2.x uses Direct Volume Control by default on 2.3+ mid-to-high end devices. On stock ROMs this produces much better audio output. But many custom/buggy ROMs, while supporting DVC, can fail with it.