In my editor log I have the info below. When I build to iOS and then archive and upload to testflight my build is 175MB. Is the 75 mb not including the .dlls? How can I find the size of these .dlls to try to eliminate the larger ones?
Textures 53.0 mb 70.4%
Meshes 5.7 mb 7.6%
Animations 249.3 kb 0.3%
Sounds 10.1 mb 13.5%
Shaders 60.9 kb 0.1%
Other Assets 486.9 kb 0.6%
Levels 750.7 kb 1.0%
Scripts 613.1 kb 0.8%
Included DLLs 4.1 mb 5.4%
File headers 248.2 kb 0.3%
Complete size 75.2 mb 100.0%
Mono dependencies included in the build
Dependency assembly - Boo.Lang.dll
Dependency assembly - Mono.Security.dll
Dependency assembly - System.Core.dll
Dependency assembly - System.dll
Dependency assembly - mscorlib.dll
Dependency assembly - UnityEngine.Advertisements.dll
Dependency assembly - UnityEngine.UI.dll
Dependency assembly - UnityEngine.Networking.dll
Dependency assembly - UnityEngine.Analytics.dll
Dependency assembly - GETween.dll
Dependency assembly - Assembly-CSharp-firstpass.dll
Dependency assembly - Assembly-CSharp.dll
Dependency assembly - Assembly-UnityScript.dll
http://forum.unity3d.com/threads/unity-5-3-x-build-size-increase-faq.383533/
The size of the app is due to the new system iOS is using. Basically, you have two apps in one (32-64bit) plus some extra info and some non-compressed data.
Once you upload to the AppStore, Apple will do the trimming and proper job and only then you will see the actual size of the app.