I started experimenting with Xamarin after they made it free with the open source announcement and I'm cautiously optimistic now. I can work around the works of Xamarin Studio (or the VS plugin) and I like C# and Swift about equally, but app startup time specifically seems subpar with Xamarin.<p>Edit: more on topic, the open source move is fantastic! I felt the money might be worth it for not only the tooling but also the top notch documentation, but I've never been able to convince any of my bosses on this.<p>Apps built with Xamarin (or a similar system where you bind to platform API's) or so much better to build and use than these cross platform platforms.