You can now pay for public transport tickets in Finland with your smartphone. The app is called Waltti Mobile, and it's available for Android and iOS devices.

When you first open the application, you will be asked to create an account and enter the phone number that you will use to make the payment. The phone number is used for billing, and it is not used for any other purpose. The app will send a confirmation code to your phone, and you will be able to make a payment using that code. The payment is made using a credit card, debit card, or other electronic payment method.