Android App Reflection

Is it possible to say, bootstrap an Android app, then use reflection to access fields from that app while it's running?

With java you can take any java application and use a class loader to create and run a new instance of the application, this then allows you to use reflection to access the fields from the application at runtime (how runescape bots work).

I'm new to android development and am not sure of the restrictions.

Any information will probably be useful, and I realize this probably isn't all that legal.