If you've installed the Alexa app on your Android smartphone, then you can set it as the default in the digital assistant settings. — dpa
When it comes to picking the default virtual assistant on your smartphone, Android is more liberal than you may think: Instead of Google's own assistant you can also opt for Amazon's Alexa as the standard application.
If you've installed the Alexa app, you can set it as the default in the digital assistant settings. Once that's done, pressing the home button for an extended period of time will open Alexa instead of Google Assistant.
However, Google Assistant will keep running in the background: That's why you'll see the microphone icon when running searches or on Google Now, for example. One thing to keep in mind, though, is that you won't be able to call up Alexa using a voice command on Android devices. – dpa
