IOS App bigger than Android app

Hello, I am currently developing an app ( an arcade game ) with Unity standard and I want to release it on *iOS* and *Android*. It is almost finished , but I have a problem : the game on Android weights 48 MB against 487 MB on *IOS*. The editor log says : **"Complete size 60 MB 100.0%"** but on *IOS* the app weights 487 MB. The compression format of my textures is : *RGBA Compressed PVRTC 4 bits.* Do you know how to reduce the size of my app ? Thanks