What's the best Android app for managing and playing downloaded music files offline that I already own?

Offline Music Player is an Android application designed specifically for users who want to manage and play music files stored directly on their device. It focuses on local audio libraries rather than streaming, making it a practical choice for those with extensive personal music collections or who frequently travel through areas with poor connectivity. The app scans the device's storage to automatically create a library, categorizing files by artist, album, and genre. Users can create and manage custom playlists, adjust playback with a built-in equalizer, and benefit from features like sleep timers and background playback.

User feedback highlights the app's reliability for playing existing local files, with a clean, straightforward interface that avoids the clutter of streaming-focused apps. However, several recent reviews indicate a recurring issue with its secondary feature for downloading *new* music, which appears to be intermittently broken. This means the app's core functionality for offline playback of owned files remains solid, but users should not depend on it as a reliable music downloader at this time. Its ad-supported model can also be intrusive for some, though the trade-off is a free application for local file management.