following link mentions that we can find element by giving id... but i am unable to find it.
https://github.com/appium/appium/blob/master/docs/en/writing-running-app
In the Appium version 1.0 onwards, findElementByTagName is deprecated.
You have to use the findElementByClassName instead with qualified class Name. Code for EditTextField and Button in android as below :
findElements(By.className("android.widget.EditText"));
findElements(By.className("android.widget.Button"));