A long-standing, open-source image editor that is completely free to use.
Portable apps are much more common on Windows (often using .exe wrappers). The macOS architecture is significantly different, relying on complex library dependencies, application support folders, and strict security permissions (like Gatekeeper and System Integrity Protection). Because of this, "Portable Mac" versions are often:
Adobe now offers a browser-based version of Photoshop for subscribers that requires no installation. Affinity Photo:
If the high cost of a full Creative Cloud subscription is the barrier, there are several professional-grade alternatives that are either free or much more affordable: