Most of you may have not noticed this, some of you may have. All apps are stored in a folder called "Mobile Applications". In that folder an app will store it's self under name. When the update came, the app would duplicate itself leaving the old version and the updated version. The updated version will the store itself under the name of the previous version but with a number(Example: TapTap, TapTap 1, TapTap 2 ect.) With the new iTunes 8, apps now store themselves with the name of the app + the version of the beside it(Example:Asphalt4 1.2.7) and automatically deletes the previous version.