Before the latest version of Android, only one option existed for keeping Google Play purchases secure is by entering your password. But if you’re using Android 6.0 Marshmallow on devices like the Nexus 5X or Nexus 6P then you’ve gained the ability to authenticate with your fingerprint instead.
Using a fingerprint is faster than typing in a complex password, and gives you the final decision on purchases if you share an account with someone else. Here’s how to set it up:
Step 1: Head to the Google Play store, open the slide-out menu and head to Settings.
Step 2: Scroll down to Fingerprint authentication and tap the check box next to it.
Step 3: Enter your password when prompted, and you’re set.
Now you can skip typing in a password for any Google Play purchases. Instead, you’ll see a pop up asking for your fingerprint.