How to accept payments on your Android device through viva.com | Terminal:
Sign into viva.com | Terminal in your Android device.
Enter the amount on the app's home screen.
Ask the cardholder to tap the card on the back of your device.
Once the transaction is successfully complete, a relevant message will appear on the screen.
You may then send the receipt via SMS/E-mail to the cardholder or print it (Bluetooth connection with a printer is required).