If you know and enjoy coding in Ruby, you intend to target only iOS, and you don't know Objective-C, C or C++ than RubyMotion is a good investment.
On the other hand, if you want to target iOS and Android you'd better learn Objective-C and Java. An interesting alternative is to use HTML5 and JavaScript if you already have a good background as a web developer.
On the other hand, if you want to target iOS and Android you'd better learn Objective-C and Java. An interesting alternative is to use HTML5 and JavaScript if you already have a good background as a web developer.