BarTong is an offline smartphone payment solution that enables users to make payments at physical stores without the need for cash or cards. The amount paid is consolidated and billed on the following month's phone bill. To use BarTong, users need to download the app for free from the App Store, authenticate their information once, and complete the payment process. Users can easily make payments by generating a barcode within the app and presenting it at participating merchants like CU, 7-Eleven, E-Mart 24, and more. BarTong prioritizes security by providing one-time use barcodes for login and automatically disabling access after five incorrect password attempts or upon reporting a lost phone to the carrier. The app also offers convenient features like generating payment barcodes with a single password input and optional fingerprint authentication.