Since last three months i been working with RhoMobile (Cross platform mobile development using Ruby).
As i came across it’s totally new domain for me, you need to understanding mobile device environment and behavior .
Major part while developing application with RhoMobile.
2) Services for different functionality
3) Jqmobile / Jquery
4) Rhodes SDK
5) Cross platform SDKs (iPhone, Android, BB)
More details and installing guide for different platform available http://docs.rhomobile.com/