Uninstall unnecessary applications and delete useless installation packages. (Perfect support for OS Catalina)

1. Find and delete installation packages that are no longer needed, which can free up a lot of disk space.

2. Use the correct method to delete unwanted apps. Remove entire applications, including all of their associated files. (E.g. caches, preferences, logs, etc.) - In-app purchase

3. Reinstall an application by resetting its related data. - In-app purchase

4. Learn how to use the "pkgutil" command tool to uninstall the installed packages.

5. Learn how to use commands to find internet, spotlight and quicklook plug-ins.