Game optimisation - file size

I am looking at how to reduce the file size of an app I have developed using unity. How do I find out the exact data that makes up the file size of the app?

 

There's a way to get some of the data you are looking for but I believe that it's buried in the build report in the Editor Log. After performing a build, access it from the Console tab menu on the right.

However, if you want to save your eyes use this: https://www.assetstore.unity3d.com/en/#!/content/8162

I started using this a while ago and I found this tool to be very helpful in showing me aspects of my project that were overly big and were in need of attention.