There are standard folders. In all cases anything stored in the Home/Library folder is unneeded as they will be reconstructed when the app is installed using an installer or when run for the first time if no installer was provided. Only apps that need store something that should not be accessible to a user, such as a registration number, is kept in the root Library or the System Library. The latter is used when only the system admin can have access. The system admin is not the same as an admin user. The former can access anything on the computer anywhere.
You can save Applications anywhere you want. For uniformity, the Unix system always puts Applications in a root directory. This way it's in the same place for and accessible to everyone with an account. However, one can move the Applications folder to another disk or location then provide an alias to the new location in the root location. Thus, anyone looking for an app in the standard location will actually see the apps in the new location. Many people use this trick if they have a small SSD and need to store the apps on another disk such as an external HDD.
When you uninstall software often you must delete more than just the application. This other stuff is found in pretty standard places making it easy to use application uninstaller instead of hunting down everything yourself. See the following. It should give you some idea of what I mean. I put it together to help users when they needed to uninstall manually.
Basics for Uninstalling Software
Most OS X applications are completely self-contained "packages" that can be uninstalled by simply dragging the application to the Trash. Applications may create preference files that are stored in the /Home/Library/Preferences/ folder. Although they do nothing once you delete the associated application, they do take up some disk space. If you want you can look for them at the above location and delete them, too.
Some applications may install an uninstaller program that can be used to remove the application. If you cannot find the uninstaller then you could download the freeware, Easy Find, to locate files that need to be removed. The places you need to search include:
- /Home/Library/Applications Support/ folder. Check if the application has created a folder then delete the folder that's in the Applications Support folder.
- Applications may install a startupitem or a LogIn item. StartupItems are usually installed in the /Library/StartupItems/ folder or the /Home/Library/StartupItems/ folder. Login Items are set in the Users & Groups preferences. Open it in System Preferences, then click on the Login Items tab. Select the item from the list and click on the Delete [-] button to remove it.
- Some software use startup daemons or agents. Look for them in /Library/LaunchAgents/ and /Library/LaunchDaemons/ or in /Home/Library/LaunchAgents/.
Some applications install a receipt in the /Library/Receipts/ folder. Usually with the same name as the program or the developer. The item generally has a ".pkg" extension. Be sure you also delete this item as some programs use it to determine if it's already installed.
There are many utilities that can uninstall applications. Here is a selection:
AppZapper
AppDelete
Hazel
AppCleaner
CleanApp
iTrash
AppBolish
AppUninstaller
Uninstaller
For more information visit The XLab FAQs and read the FAQ on removing software.
Hope this all is informative.
