Modern Android Music Player Development

I'm seeking a seasoned Android developer to create a sleek, modern music player app with the following features:
- Playlist creation: Users should be able to easily create, edit, and delete their own playlists.
- Equalizer settings: The app should allow users to customize their sound experience with adjustable equalizer settings.
- Offline playback: The music player should be capable of playing downloaded tracks without an internet connection.
- Sleep timer: A sleep timer function is required to allow users to set a timer for the music to stop playing.

The design of the app should embody a modern and sleek aesthetic. As for audio format support, the app primarily needs to handle MP3 files.

Ideal skills for this project include:
- Proficiency in Android app development.
- Experience in audio app development.
- Strong UI/UX design understanding for a modern aesthetic.
- Knowledge of working with audio formats and equalizer settings.

Please provide examples of similar projects you've completed in your proposal.