You can determine the amount of storage space that any of your iPhone’s apps are occupying by visiting General > iPhone Storage in the Settings app. Fortunately for those with jailbreaks, there’s an easier way.
Enter Taille, a newly released and free jailbreak tweak by iOS developer MTAC that permits users to ascertain the storage occupancy of any installed app by using a simple 3D Touch (or Haptic Touch where applicable) gesture on its respective Home screen icon.