SimpMusic, a FOSS YouTube Music client for Android, receives high praise for its user-friendly interface and extensive features, including Spotify login for Canvas and Lyrics, and Musixmatch for translated lyrics. Users appreciate its design, battery efficiency, and the ability to transfer Spotify liked songs via a Python script. While some minor playback issues and lyric sync problems are noted, the app is lauded for its intuitive experience and open-source nature, making it a standout alternative to other music clients.