Money transfer & wallet Mobile app (iOS / Android)
CoinPal — a coin-transfer & messaging app for sending between users

Pick a recipient in seconds.send coins to each otherP2P money-transfer & messaging app.

Digital Coin, Inc. — Users send coins to one another, specify recipients by QR code, and communicate via chat. A mobile app that syncs transfers, balances and notifications in real time, built from scratch.

Seconds
Transfer speed
Select recipient → send
Real time
Sync of balances, arrivals and notifications
Socket.IO two-way sync
QR + chat
Recipient selection and communication in one app
QR scan + chat
Challenge
Before

Small transfers among friends were cumbersome with cash hand-offs or bank transfers, while recipient-selection mistakes and slow arrival confirmation hindered casual exchanges.

  • Send coins to friends easily, on the spot
    Cash and transfers are cumbersome
  • Specify the recipient quickly and accurately
    Worried about number/account input errors
  • Check balances and arrivals right after sending
    Slow updates cause worry
  • Stay in touch with the person you sent to
    Communicating outside the app is messy
Solution
After

Specify a recipient by user search or QR code and send coins. Socket.IO syncs balances, incoming funds and notifications in real time; in-app chat handles communication. Laravel Passport secures authentication, and images are stored in AWS S3.

Recipient selection ～ coin transfer ～ real-time arrival: an end-to-end flow Sender App user Select recipient QR / search Coin transfer Balance update Balance sync Socket.IO Receiver Instant arrival Push notifications + chat for communication Real-time & security foundation Socket.IO sync Balance & arrival, two-way Passport auth OAuth2 tokens OneSignal alerts Arrival push Sync transfers, balances and notifications in real time for safe sending
app.coinpal.example.jp/transfer
Balance 1,250 Recipient Coins to send 300 coin 123 Send 300 coin Balances and arrivals reflect in real time right after a transfer
Transfer screen — specify a recipient and send coins (balances and arrivals reflect in real time)
Tech stack React Native Redux Toolkit Socket.IO AWS S3 OneSignal
6months
20person-mo
Considering adopting this at your company? → info@amela.vn