For Android users, when you access to the Google Play Store and download paid applications via mobile data, Play Store will prompt out different payment methods for you to pay for the app.
If you select StarHub billing, a silent SMS will be sent out to the Google servers, the payment for the app will appear in your phone bill at the end of the month. In addition, the silent SMS that was sent is considered an international SMS. For all international SMSes originating from Singapore, redONE charges a $0.15/SMS sent. Roaming charges will apply if the SMS is not sent out from Singapore.