Can we find element by ID in appium

You can use element ID as following:-

package name : com.example.testap

Element ID : txtLogin

write the following code -

 driver.findElement(By.id("com.example.testapp:id/txtLogin")).sendKeys("abc");

Here is the jave code with most common ways to locate elements using Appium

//Find element by id and enter Hello in Text box.    driver.findElementById("edit_name").sendKeys("Hello");    //Find element by class name and enter Hello in Text box.     driver.findElementByClassName("com.android.EditText").sendKeys("Hello");    //Find element by xpath and enter Hello in Text box.    driver.findElementByXPath("//cass[@value='Enter Name']").sendKeys("Hello");    //Find element by link text and enter Hello in Text box.    driver.findElementByLinkText("Enter Name").sendKeys("Hello");

If you want to learn more ways to find elements in appium for native and webviews VISIT HERE

You can find by id using Xpath too,e.g.here element has class="android.widget.Button" and id="digit5" so you can find like

xpath("//android.widget.Button[contains(@resource-id,'digit5')]")

Xpath is most useful when you want apply Multiple condition likexpath("//android.widget.Button[contains(@resource-id,'digit5') and @text='5']")for more details you can see on http://www.software-testing-tutorials-automation.com/2015/10/ui-automator-viewer-get-android-app.html