Greypaint

Greypaint checks Sparkle, Homebrew, GitHub, and the App Store, and answers in one list. Every Mac app shows up with its current version, the version available, and a single Update button. It includes rollback if an update breaks something, autopilot mode for hands-off updates, and major-version flags so you can hold back when a new release might change behavior. 14-day free trial, then $6.49 lifetime, no subscription.