Platform wars are not just for users, it haunts developers equally. iOS, Android and Windows Phone are the 3 major platforms that gives devs a hard time. Google has its own challenges as a company that publishes a large array of web tools that it intends to optimize for mobile users across all these platforms. Google has Maps, Search, Gmail, Drive, Docs, Plus amongst others that needs to work well on mobile. While Google has been aggressive with Apps for iOS, it seems they are willing to make life easier for other developers too.
Google has published its open source j2objc tool that converts Java code to Objective C. This should make the life for several developers much easy. Making apps across platforms is a huge porting effort and this little tool by Google would help a bit. Google mentions that they use the tool themselves, but we aren’t sure to what extent and for which apps. The quality of the tool is said to be between alpha and beta.
While j2pbjc can ease some difficulties of porting an app, the tool makes it clear that it won’t help you with UI work. Front end needs to be done using the specific SDK requirements.
iOS UI code needs to be written in Objective-C or Objective-C++ using Apple’s iOS SDK