eg. According to titanium backup, the total size of Jelly defense is 51.6MB whereas android says that it's 112KB
Angry Birds size is 18.5MB according to titanium but only 1.30MB in android.
Skype is 16.7MB according to titanium but only 2.11MB in android.
(I hope this thread is in the right place, if it's not feel free to move it)