Parse has first-party SDKs for Windows Phone, OS X, iOS, JS, and Android. There are third-party interfaces for many languages (PHP, Ruby, etc). It's not an Apple-only solution.
Heroku is the platform of choice for thousands of iOS, Android, Windows Phone, (and mobile web, of course) applications.
This screencast was merely a demonstration of what a rapid iOS development workflow with the Core Data Buildpack looks like.