App file size differences in Android and iOS

Question

Working with both app distributions services (android market and Apple App store) I have discovered a mystery.

The file size of an app is in general larger for an Apple a

Answer 1

For a universal app in iPhone we need to put three size of images -

one for 320x480 px
second for 640x940 px (retina)
third for 768x1024 (iPad)

where as while developing a android application we need to put three kind of images -

hdpi (high)
mdpi (medium)
ldpi (low)

one more thing here in android there is no compulsory rule to put all three kind of images. Basically it depends on for which target you are making app , only for those resolution we need to put images.