If you're interested in user experience and responsive design, iOS/Android development might be the field for you! It's not particularly difficult to get started, but iOS/Android development is very difficult to master. You can open up a new world of career possibilities, whether you have previous web design or development experience or not. It's an exciting world full of limitless possibilities, and, who knows? You could be the architect of the next big thing in the Apple app store or Google play Android marketplace!
It can be difficult to find a cross-platform framework for simultaneous iOS/Android development, but there are services and companies out there to provide help with creating similar or identical apps in both verticals. Alternatively, if you're making Android apps in Java, for example, you can hand code an app to create it in iOS. This might not be the most fun thing to do, but you'll certainly become an iOS/Android development legend!
In fact, there are lots of schools of thought about iOS/Android development. Because it can be difficult to master even one of these worlds, some coders choose one platform and stick with it. If you work with a responsive design or user experience company, you might be assigned one coder while creating your iOS app, and another for your Android/Google play app. Many independent contractors, however, try to master both sides of iOS/Android development, so that they can offer a full range of services for a better price.
iOS/Android development can be thought of as two distinct fields, or one mega field. And depending on your preferences for coding and responsive design, you might want to focus on one platform. Breaking into either form of development requires lots of practice, education, and trial and error, and collaboration along the way. Best of luck to you, aspiring app maker!