wtf is boo?

Boo is a small macOS menu bar app that watches your Downloads folder and automatically moves files into organized folders. When you download something it recognizes, a little ghost icon in your menu bar animates to show it eating the file and moves it to the appropriate folder, such as Images, Archives, or Documents. For file types it has never seen before, it shows a confused expression and asks you where that type of file should go, then remembers your answer for future downloads. The app is built as a native Swift application with no web technologies or heavy runtimes underneath it, which keeps it small at a couple of megabytes. It runs in the background and only watches the Downloads folder, it never touches any other part of your filesystem. The ghost icon changes expression depending on what it is doing: watching, eating, confused, napping, or happy. There is also a toast notification system that briefly shows a message like "Nom! Saved to Images" when a file gets sorted. Settings let you pause the sorting, turn toast notifications on or off, and review or change the rules you have taught it for unknown file types. Boo has no network code at all. It cannot upload files, send analytics, or check for updates in the background. The only connection to the outside world is a menu item that opens your browser to the GitHub releases page so you can manually check for new versions. It runs in the macOS App Sandbox, which means the operating system itself limits what the app can access to just the Downloads folder. The app is not notarized (which requires a paid Apple Developer account), so macOS will initially block it as an unidentified developer app. The README explains how to approve it through System Settings. SHA-256 checksums are provided for each release so you can verify the download before running it. File-type sorting rules and the ghost's SVG artwork can both be customized by editing the source code. The project is MIT-licensed.