Paily: A Payment Wallet for Travelers in Vietnam
Payments should not require exchanging money
International visitors to Vietnam often exchange money, carry cash and look for a counter to pay. Paily was built as a super app for the trip: a wallet for paying by QR code at merchants, exchanging currency and planning spending.
The app has a wallet, a favorites list and a profile. The wallet shows the balance, top-up, receive and QR scan. The home screen suggests places nearby, and there is an assistant that helps plan a travel budget.
QR payments with crypto, then bank links
QR payments with crypto work, and the wallet is linked to several banks. This was the most time-consuming part of the project. To move money out through the banking system, I had to apply for a license and work with the parties involved. That step took three months.
It showed me that a payment product is more than software. A piece of code can run in a few days, but getting money through the banking system takes time from people and from legal processes. I learned that while standing between the product and the paperwork.
Where it stands today
Paily is still running. It started in the Da Nang market. The repository records 269 commits, from December 2024 to August 2025. The stack is Flutter, Dart and Firebase, and the crypto part uses Solana. I planned the features, designed the product and wrote the code myself.
Tech Stack
Flutter
Dart
Firebase
Solana