frist application screen
screen for hint contact for receive OTP by phone number
screen for hint contact for receive OTP by email
screen for OTP validation
screen for personnal user pin for enchance security
dashboard screen with raw options like deposit , withdraw for mobile money service (currently simulate) send money and receive
add money in your lynq app from mobile money service ( simulated)
send money from lynq to your mobile money service ( simulated)
send money to a link user in your contact list or using qr code
receive money from a other wallet

Inspiration

Every year, the Senegalese diaspora sends over $2.5 billion in remittances back home. While services like Wave have revolutionized local money transfers with 1% fees, the real challenge lies in international transfers and the cumulative cost of frequent transactions.

When money crosses borders — from France to Senegal, or the U.S. to Dakar — the costs skyrocket. Currency conversion fees. International transfer commissions. Bank intermediaries.
What starts as a simple act of family support becomes a complex and expensive process. And for those who send money regularly, even that “small” 1% quickly adds up to major losses.

We met Awa, a small shop owner in Dakar. She told us:

“My brother in France sends me money ten times a month to help with my shop. Each time, I pay 100 FCFA in fees. That’s 1,000 FCFA lost every month — a full day’s profit gone. And since he sends euros, there are extra conversion fees I don’t even understand. I just know I always receive less than what he sends.”

We also spoke with Moussa, who lives in Paris and feels the frustration from the other side:

“I want to send money instantly to my mother, but Wave limits international transfers. I have to use Western Union or bank transfers — the fees are awful, sometimes 5–8%. And it takes several days. When my mother needs money urgently, I feel powerless. The technology exists to do better. Why can’t sending money be as simple as sending a message?”

Then there’s the bigger problem: millions of unbanked Senegalese who lack access to traditional financial services. Merchants who want to accept international payments but can’t afford card processing fees. Students abroad struggling to pay tuition. SMEs wanting to trade internationally but trapped in a financial infrastructure designed for the wealthy.

What it does

Lynq is a mobile money app that makes transfers in Senegal instant, international, and 95% cheaper than existing solutions. It’s designed to feel familiar — like Wave or Orange Money — but powered by the Bitcoin Lightning Network for seamless, borderless payments.

Core Features

Money Transfers

Send and receive FCFA with instant settlement via the Bitcoin Lightning Network
Internal Lynq-to-Lynq transfers (person-to-person)
Lightning payments — send/receive from any Lightning wallet worldwide
QR Code payments — generate dynamic QRs to receive money
Real-time transaction updates with automatic polling

User Management

Login via phone number or email with OTP verification
4-digit PIN to secure transactions
Contact management — favorites, phone contact sync, user search
Profile editing — name, email, account details
Identity verification (KYC) — ID card, passport, or driver’s license

Wallet

Dual-currency display — FCFA by default, BTC optional
Real-time balance updates
Transaction history with filters (date, type, amount)
Transaction status tracking (pending, completed, failed)
Manual refresh (pull-to-refresh)

Notifications

Push notifications via Firebase
Price alerts — get notified of BTC/FCFA rate changes
Instant payment confirmations

User Experience

Dark mode support
Multilingual ready (French first)
Offline detection with clear error messages
Responsive design — works on all screen sizes
Smooth animations and haptic feedback

The Magic: How It Works

User A (in Paris) wants to send 10,000 FCFA to User B (in Dakar).
They enter the amount in FCFA, select a contact, and confirm with their PIN.
The backend converts FCFA → BTC at the real-time rate (locked for 5 minutes).
The Lightning Network transmits the payment in under 1 second.
The backend converts BTC → FCFA.
User B receives 10,000 FCFA in their wallet.
Both users receive a push notification.

Total time: < 4 seconds | Total fees: < 5 FCFA

How we built it

We designed Lynq as a full-stack mobile application, built with cutting-edge technology — optimized for speed, security, and simplicity.

Frontend – Flutter Mobile App

Why Flutter?

We chose Flutter to code once and deploy on both iOS and Android — essential for reaching the widest audience in Senegal, where both platforms are widely used.

Tech Stack

Framework: Flutter 3.x (Dart)
State Management: GetX — reactive programming + dependency injection
API Integration: Retrofit + Dio — type-safe HTTP client with auto code generation
Local Storage: flutter_secure_storage — AES-encrypted storage for sensitive data
UI Components: Material Design + Cupertino widgets for cross-platform consistency
Responsive Design: flutter_screenutil — adapts to all screen sizes
Animations: flutter_animate — smooth and delightful transitions

QR Features

QR Generation: qr_flutter
QR Scanning: mobile_scanner

Push Notifications

Firebase Cloud Messaging (FCM)

Fonts & Contacts

Google Fonts — polished typography

Challenges we ran into

Challenges Faced

1. Learning Curve of the Lightning Network

Problem:
None of us had prior experience with the Lightning Network. The documentation assumes deep Bitcoin knowledge (BOLT11 invoices, liquidity, payment preimages, etc.).

Solution:

Intensive documentation study
Created proof-of-concept test scripts
Built abstracted functions to hide complexity
Philosophy: completely hide Lightning from the user

2. Transaction Status Uncertainty

Problem:
Lightning payments aren’t instantly confirmed like a database transaction. There’s a 1–5 second window of uncertainty.

Solution:

Built an advanced polling service
Clear user statuses:
- “In progress…”
- “Completed!”
- “Failed” (with retry option)

3. Positioning Against Wave

Problem:
During user testing: “Wave is already great and only charges 1%. Why switch?”

Solution:
Message Repositioning:

Old: Lynq is cheaper than Wave
New: Lynq does what Wave can’t — international transfers, frequent remittances, cross-border payments
Coexistence: Wave for local, Lynq for international

Accomplishments that we're proud of

1. Production-Ready MVP in 30 Days

We delivered:

31 functional API endpoints
5 key modules (auth, home, contacts, profile, KYC)
19 backend features fully integrated
Complete Flutter app (iOS & Android)
Error messages in French
Push notifications, QR code, real-time polling

Keys to success:

Clear architecture from day one
Parallel frontend + backend development
Daily progress tracking

2. Successful Lightning Network Integration in Africa

Lynq is one of the first African apps to integrate Lightning for daily payments.

No visible Bitcoin layer for users
Settlement in < 1 second
Near-zero fees (< 5 FCFA)
Handles edge cases (expired payment, routing failure, etc.)

3. A Real Crypto App for Real People

Unlike most crypto apps, Lynq is simple.

User Testing Results:

Users understood how to send money in < 30 seconds
No one asked “What is Bitcoin?”
“Looks like Wave” = instant trust
Works even on unstable connections

UX Design:

FCFA-first (crypto hidden)
Clear French messages
Immediate feedback for every action
Dark mode
Smooth animations

4. Real Savings for Real People

For Awa (merchant):

Before Lynq: 1,000 FCFA/month in fees
With Lynq: 50 FCFA/month
Savings: 950 FCFA/month = 11,400 FCFA/year (~$18.50)
Equivalent to 2 full days of profit

For Moussa (diaspora):

Before: 500–800 FCFA per transfer
With Lynq: < 5 FCFA
Savings: ~99%

At scale:

10,000 users × 5 transfers/month
Before: 5,000,000 FCFA in fees
With Lynq: 250,000 FCFA
Savings: 4,750,000 FCFA/month (~$7,700)
Enough to fund food, healthcare, education…

What we learned

Initially, we were skeptical about Bitcoin’s practicality for everyday use.
After building Lynq, we’re convinced that the Lightning Network is the future.