To switch between contexts in appium versions < 1.4.3 I used in C#:
var contextNames = driver.GetContexts();
driver.SetContext(contextNames[1]; ///for webview_1, for native_view 0
for the latest appium I had to change this code to only:
driver = new AndroidDriver<AppiumWebelement)(new Uri(“http://127.0.0.1:4723/wd/hub”), capabilities);
…some code here
driver.Context = “NATIVE_APP”;
so in your case it would be driver.Context = “WEBVIEW_1”;
hope this helps…took me a day to figure out the code change.