Android phones, apps and tablets

If you go into:

Settings > Apps

And select an app.

If the app says "Uninstall" then it hasn't duplicated itself.

If the app says "Uninstall Updates" then it has duplicated itself.

Anything shipped with the OS is definitely duplicated (Gmail, Maps, etc on regular Android, things like Facebook and Samsung on a Galazy S3, etc).

Anything installed but somehow declared as being special (some of Google apps, some of the weird printing services from HP and others) will also have duplicated themselves.

First few I hit...
"Uninstall"
Drive
Play Music

"Uninstall Updates"
Gmail
Play Services

Terms of GApps mean Cyanogenmod isn't permitted to distribute as part of the main installable, you have to download whichever gapps.zip suits your version.