I have an app using Xamarin.Forms targeting IOS, Android and WP 8.
I need push notification feature in my app.
I have seen the pushsharp demos
In Xamarin Forms you could also use a notifications SDK like Donky (which is the European equivalent to the American Urban Airship); you can easily make a scalable notifications project in a single day, I've twice built WhatsApp clone shells in under 35 minutes each time using this SDK. See http://docs.mobiledonky.com