How to reduce the app size? Xamarin Forms

I have managed to reduced the app size by setting the linking to "Sdk and User Assemblies" and making a release build but my app size is still too large. (11mb) Are there any other ways to reduce the size?
I have created a new xamarin forms project using the visual studio 2017 cross platform pcl template and not added anything else. The app size is currently 11mb. This is a basic new project which gets created from visual studio 2017. Surely 11mb is too big?