What counts as an app leftover?
Many Mac apps store settings and support data outside the app bundle. Common locations include ~/Library/Preferences, ~/Library/Caches, ~/Library/Application Support, containers, logs, and receipts.
AppTidy shows why each file matched
Cleanup is safer when you can see the reason. AppTidy separates stronger matches from review items so shared folders, fuzzy names, and generic leftovers do not disappear without your choice.
Leftovers screen for orphaned files
The Leftovers screen can scan for abandoned caches and support folders that no installed app clearly owns. It stays review-only because developer tools and shared frameworks often use generic folder names.