When I need to "get rid of" an app, I use the free "AppCleaner".
Get it here:
Then, do this:
1. Open AppCleaner
2. Open your Applications folder (in the finder)
3. Grab the app you want to delete, and "drag and drop" it into AppCleaner's window.
4. AppCleaner will "look around" and gather up all the files related to the app.
5. If any are "unchecked", put a check into them.
6. Click the "remove" button, and they're ALL moved to the trash.
7. Close AppCleaner and empty the trash.
8. Gone!
I'm guessing there might be a few applications that AppCleaner can't "clean out" (perhaps Adobe stuff, Microsoft stuff, etc.). Those software publishers usually make available a standalone "uninstall" utility to get rid of them.