add tag view for android

README.md

@@ -159,6 +159,22 @@ els = self.driver.find_elements_by_android_uiautomator('new UiSelector().clickab
 self.assertIsInstance(els, list)
 ```
 
+### Finding elements by Android viewtag search
+
+This method allows finiding elements using [View#tags](https://developer.android.com/reference/android/view/View#tags).
+This method works with [Espresso Driver](https://github.com/appium/appium-espresso-driver).
+
+Adds the methods `driver.find_element_by_android_viewtag` and `driver.find_elements_by_android_viewtag`.
+
+```python
+el = self.driver.find_element_by_android_viewtag('a tag name')
+self.assertIsNotNone(el)
+```
+
+```python
+els = self.driver.find_elements_by_android_viewtag('a tag name')
+self.assertIsInstance(els, list)
+```
 
 ### Finding elements by iOS predicates
 

appium/webdriver/common/mobileby.py

@@ -20,5 +20,6 @@ class MobileBy(By):
     IOS_UIAUTOMATION = '-ios uiautomation'
     IOS_CLASS_CHAIN = '-ios class chain'
     ANDROID_UIAUTOMATOR = '-android uiautomator'
+    ANDROID_VIEWTAG = '-android viewtag'
     ACCESSIBILITY_ID = 'accessibility id'
     IMAGE = '-image'

appium/webdriver/webdriver.py

@@ -341,6 +341,30 @@ def find_elements_by_android_uiautomator(self, uia_string):
         """
         return self.find_elements(by=By.ANDROID_UIAUTOMATOR, value=uia_string)
 
+    def find_element_by_android_viewtag(self, tag):
+        """Finds element by [View#tags](https://developer.android.com/reference/android/view/View#tags) in Android.
+        It works with [Espresso Driver](https://github.com/appium/appium-espresso-driver).
+
+        :Args:
+         - tag - The tag name of the view to look for
+
+        :Usage:
+            driver.find_element_by_android_viewtag('a tag name')
+        """
+        return self.find_element(by=By.ANDROID_VIEWTAG, value=tag)
+
+    def find_elements_by_android_viewtag(self, tag):
+        """Finds element by [View#tags](https://developer.android.com/reference/android/view/View#tags) in Android.
+        It works with [Espresso Driver](https://github.com/appium/appium-espresso-driver).
+
+        :Args:
+         - tag - The tag name of the view to look for
+
+        :Usage:
+            driver.find_elements_by_android_viewtag('a tag name')
+        """
+        return self.find_elements(by=By.ANDROID_VIEWTAG, value=tag)
+
     def find_element_by_image(self, png_img_path,
                               match_threshold=DEFAULT_MATCH_THRESHOLD):
         """Finds a portion of a screenshot by an image.