App Fixer – return any app to default settings by removing corrupt plist files and saved application states
Boot Buddy – a free utility for creating macOS bootable installer drives.
ConsoleSpy – a free utility for software developers, security analysts and other bug hunters.
Critical Updates – a free utility to monitor updates to XProtect, Gatekeeper and friends.
DetectX – find source files for apps that can cause performance problems on your mac
FastTasks 2 – general troubleshooting app for when things go wrong with your mac