In iOS, things are simple. The deallocating code is very concise and safe. Why having the performance overhead of smart pointers?
On the other hand, it could be useful to have them in Java and avoid manual destruction. However, this wasn't investigated :(
I'm sorry if this wasn't clear. The purpose of building this library was to have something which could be distributable to any mobile developer, not just the ones using Xamarin. If you did it through Xamarin, you could only give it to Xamarin developers, which is very limiting. We need something that could be importable by most developers, especially native SDK ones.