It is possibly just me and I don't know much about the tech involved. But it takes up 1.57 gb at the last count! It is the most massive app I have by quite some way, Netflix is the next biggest one and it's nearly three times smaller and has 2 offline video downloads. I keep having to delete things from my iPhone 5 because it's taking up so much space. It's not storing photos or other files offline, is it, so I fail to see why it is so large! Perhaps someone can enlighten me?