I have used Xamarin for years, but now I feel the framework is mature enough to use in large scale production apps. Xamarin got a lot of attention the when Microsoft acquired them. Microsoft made Xamarin available for free with Xamarin Studio or Visual Studio Community and made the code open source. With the increased user mass, we can expect increased support, both officially and in other channels like Stack Overflow, Slack or Xamarin forums. Microsoft can now offer a better story to their developers, .Net developers can create apps for just about every platform with C# (or F#).