tl;dr: Window Sweaters is a macOS menu-bar app that decorates window borders with knitted-style patterns, featuring hand-picked colorways for 37 popular apps and auto-generated designs that sample icon colors for everything else. It's installable via Homebrew or a release ZIP, requires Accessibility permissions, and uses private macOS window APIs (so updates may break it). The project is open-source (GPL-3.0), built on JankyBorders, and supports custom colorways via config files.