When trying to deploy an app in Android Device, VS is stuck here:
1>C:\\Users\\George\\AppData\\Local\\Android\\android-sdk\\build-tools\\23.0.1\\zipalign
Actually, it seem to be a bug with Xamarin. I don't know since wich version this bug occur, but i have the same problem since i have updated to the last Builds.
This bug is occuring with my Amazon Kindle Fire. After some test, it seem that this is not really zipalign that is buggy, but the process of attaching to the Device that hang/fail afterward.
In order to be able to debug my Android platform, the only workaround i have found at the moment is to debug via an Emulator. I have used Android_Accelerated_x86 (Android 6.0 - API 23) Emulator that is shipped with the last versions of SDK.
I don't know if this Emulator is Xamarin related or from the Android SDK, but you can find it in the list of debuggable devices in Visual Studio when on Android platform as startup project.
I can deploy on this Emulator and debug on it. At least we can work and debug till this bug is fixed somehow.
Good luck!