Thanks for your response. It's what I was initially taught - just drag the .app file to the trash. That's what I did. It works great most of the time, but, periodically, I'd find that it still left files behind.
When I went to the Apple Store to ask about it, an employee said that it's not always 100% in catching every file. He did suggest manually searching for orphaned files and removing them that way. Since I'm not the most technologically inclined, I didn't want to do that. CCleaner was recommended to me by numerous other Mac owners, so I tried it once. It DID find orphaned files to remove, but I never ran the program again, and deleted it.
I prefer to have only Apple programs on my iMac. But, I did see the benefit from using a cleaner. (Thankfully, I never fell for the MacKeeper scam.)
If cleaners aren't necessary, what do you do if you start noticing some lag in your computer's speed? Sites take longer to open and going from screen to screen takes longer... Especially when you have ample memory.