Add unlimited fingerprints. Unlock your smartphone with any of your fingers. Well, an Android smartphone with a fingerprint scanner allows you to add a maximum of five fingerprints to unlock your device. But don't worry, as there's this really simple hack that you can use to add as many fingerprints as you want to unlock your smartphone.
1. Go to Security > Fingerprint > Add fingerprint.
2. Now, place your finger on the scanner and place a different finger everytime you feel a vibration.
3. You're ready to rock!