Apps to Auto fetch album covers

Qmmp is a free and open-source audio player designed for various operating systems, known for its lightweight nature and extensive customization options through plugins. It provides a familiar interface similar to classic audio players while offering modern features like streaming, media conversion, and library management.

gmusicbrowser is a highly customizable, open-source music player and library manager designed for users with large audio collections. It offers a range of advanced features including intelligent playlists, flexible tagging, and extensive interface customization, making it a powerful alternative to mainstream music players.

Quod Libet is a highly extensible GTK+-based audio player for Linux, focusing on powerful music library management and flexible tagging. Written in Python and using the Mutagen library, it offers extensive customization and handles diverse audio formats seamlessly.

Rhythmbox is a powerful and versatile open-source music player designed for GNOME desktops. It offers a comprehensive suite of features for managing and enjoying your digital audio library, including playback, organization, podcast support, internet radio streaming, and seamless integration with online music services.