Anroid or Ror for foreign freelance exchanges?

Question

Android

Good afternoon!
In the future I plan to do freelance development on these exchanges (odesk, etc.) and I just can’t choose a direction. Initially focused on Android. But, I was prompted here, and in other answers I read that there is very little pure android, and accordingly, there is more competition, but in conjunction with ios, quite a lot, 90 percent. How much is this true? I was interested in pure android and without being tied to the web.
I also considered RoR, mainly due to the fact that in the future you can reach a good level of payment, and I like ruby, but as I understand it, knowledge of the entire stack of web technologies (JS, CSS, HTML, etc.) .e)? Does a freelance Rails developer need to know both front-end and back-end development?
I would like to know the opinion of programmers working in these areas on foreign freelance exchanges.
Thanks

Answer 1

but as I understand it, here you also need knowledge of the entire stack of web technologies (JS, CSS, HTML, etc.)

This is 10% of what you need to know.

Does a freelance Rails developer need to know both front-end and back-end development?

Should know, but usually there is a layout designer, and if there is a lot of JS, then there is a separate front-ender.
As for Android development, you need to choose between software (Java) or games (C++ or C#). Because the instruments are very different.