I&#x27;ve dabbled with this JavaScript for native code since 2010-11. Appcelerator Titanium SDK (now Appcelerator), Telerik, RubyMotion, Xamarin and of course PhoneGap (including PhoneGap Build). I&#x27;ve not used Xamarin, but putting it there to give a broader picture.<p>Please don&#x27;t get me wrong, I&#x27;d love to use ECMAScript(, CSS and markup) to do all web, native and server side development. Unfortunately they are marred by poor API support, performance and customization. Last two are extremely critical for non-trivial apps.<p>If you are building run of the mill simple apps like - news feed, photo, video and reading etc. You&#x27;ll be okay with anyone of the above &#x27;web stack&#x27;.<p>Here&#x27;s the litmus test. Ask the Reactive Native team to port their non-trivial paper app or mission critical messenger app or main app to Reactive Native. They are using Reactive Native for a lame duck Groups and some ad manager app.<p>JavaScriptCore is one layer deeper than wrapping a UIWebView, but it&#x27;s several layers from true native.