Deleting an application by simply dragging it into the Trash bin does not remove everything. Left behind are preferences, logs, plist files, caches, and sometimes even the PKG or DMG installer. These left over files are usually small and are left behind so if you ever re-install the application later after deleting it, it can simply pick up your preferences, ect and set itself up the way you previously had it set up. However if you never plan on re-installing the application or just want to keep your Mac clean and tidy there are a few great apps for deleting all traces of an application.
Tag / mac apps
Torrents are great for downloading and sharing files. Unfortunately they get a bad name because they’re usually used for downloading copyright movies, TV shows and other copyright files. It is not illegal to download and use torrents, however when used to download copyrighted material it is.