Souk is a third-party standalone application, a flatpak-based application store written with GTK4 and Rust that works on both desktop and mobile devices such as PinePhone, PineTab and Librem 5.
Souk is developed by "Felix Häcker" and could be a solution to the problems faced by GNOME lovers today (poor performance even on high-performance hardware).
GNOME software (App Store) for the GNOME desktop environment, comes as default for many Linux distributions, such as Ubuntu, Fedora, etc.