RiderWatch - Riders Net Profit Watch App

A cross-platform fullstack application that helps delivery riders track their trips, fuel costs, expenses, and calculate true net profit. Available as a Flutter mobile app backed by a Node.js/Express REST API.

Download APK: Google Drive · Mobile App Repo: RiderWatch

The Problem

Delivery riders on platforms like PickMe, Helago and Uber Eats see their gross earnings in the app but that number doesn't reflect reality. After fuel, vehicle maintenance, platform fees, and time costs, a rider's actual take-home can be significantly lower. Most riders don't track this accurately.

RiderWatch solves this by giving riders a clear, real-time view of their true net profit.

Tech Stack

Layer	Technology
Mobile App	Flutter (Dart)
State Management	Riverpod
Backend API	Node.js, Express
Database	SQLite (via better-sqlite3)
Auth	JWT
Charts	fl_chart (Flutter)
Local Storage	SharedPreferences

Key Features

📊 Trip Tracking

Log each delivery trip: start/end time, distance, platform, earnings
Auto-calculate trip duration
Tag trips by platform (PickMe, Helago, Uber Eats, FoodPanda, etc.)

⛽ Expense Tracking

Log fuel fills: amount, price per litre, odometer reading
Automatic fuel efficiency calculation (km/l)
Other expense categories: maintenance, food, parking

💸 Net Profit Dashboard

Real-time net profit = Gross earnings − Fuel − Other expenses
Daily, weekly, and monthly breakdowns
Visual charts with trend analysis

🎯 Goal Setting

Set daily/monthly earnings targets
Progress bar showing how close you are to your goal
Alerts when on track vs. falling behind

📱 Offline-First

All data stored locally on-device
Syncs to backend when connected
Works fully offline — important for riders in low-signal areas

Architecture

Flutter App (Mobile)
│
│  HTTP/JSON (when online)
▼
Node.js / Express API
├── /auth          Login, refresh tokens
├── /trips         CRUD trip records
├── /expenses      CRUD expense records
└── /stats         Aggregated profit stats
│
▼
SQLite Database
(also mirrored locally in Flutter via SharedPreferences)

Flutter App Structure

lib/
├── main.dart
├── providers/
│   ├── auth_provider.dart
│   ├── trip_provider.dart
│   └── expense_provider.dart
├── screens/
│   ├── dashboard_screen.dart
│   ├── add_trip_screen.dart
│   ├── add_expense_screen.dart
│   └── stats_screen.dart
├── widgets/
│   ├── profit_card.dart
│   ├── trip_list_tile.dart
│   └── earnings_chart.dart
└── services/
    ├── api_service.dart
    └── local_storage_service.dart

Key Code: Net Profit Calculation

// providers/trip_provider.dart
@riverpod
class TripNotifier extends _$TripNotifier {
  @override
  List<Trip> build() => [];

  double get totalEarnings =>
    state.fold(0.0, (sum, t) => sum + t.earnings);

  double get totalFuelCost =>
    ref.read(expenseNotifierProvider)
       .where((e) => e.category == 'fuel')
       .fold(0.0, (sum, e) => sum + e.amount);

  double get netProfit => totalEarnings - totalFuelCost -
    ref.read(expenseNotifierProvider)
       .where((e) => e.category != 'fuel')
       .fold(0.0, (sum, e) => sum + e.amount);
}

Backend API (Node.js)

// routes/trips.js
router.get('/', authenticateToken, async (req, res) => {
  const { userId } = req.user;
  const { from, to } = req.query;

  const trips = db.prepare(`
    SELECT * FROM trips
    WHERE user_id = ?
      AND date BETWEEN ? AND ?
    ORDER BY date DESC
  `).all(userId, from ?? '2000-01-01', to ?? '2099-12-31');

  res.json({ success: true, data: trips });
});

router.post('/', authenticateToken, async (req, res) => {
  const { platform, earnings, distance, duration, date } = req.body;
  const { userId } = req.user;

  const result = db.prepare(`
    INSERT INTO trips (user_id, platform, earnings, distance, duration, date)
    VALUES (?, ?, ?, ?, ?, ?)
  `).run(userId, platform, earnings, distance, duration, date);

  res.status(201).json({ success: true, id: result.lastInsertRowid });
});

Database Schema

CREATE TABLE users (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  username TEXT UNIQUE NOT NULL,
  password_hash TEXT NOT NULL,
  created_at TEXT DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE trips (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  user_id INTEGER REFERENCES users(id),
  platform TEXT NOT NULL,
  earnings REAL NOT NULL,
  distance REAL,
  duration INTEGER,        -- minutes
  date TEXT NOT NULL,
  created_at TEXT DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE expenses (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  user_id INTEGER REFERENCES users(id),
  category TEXT NOT NULL,  -- fuel | maintenance | food | other
  amount REAL NOT NULL,
  note TEXT,
  date TEXT NOT NULL,
  created_at TEXT DEFAULT CURRENT_TIMESTAMP
);

Challenges & Solutions

Challenge: Offline-First Sync

Riders often work in areas with poor connectivity. The app needed to work fully offline and sync data when back online.

Solution: All writes go to local SharedPreferences / SQLite first, with a background sync queue. On reconnect, the app pushes queued changes to the API and resolves any conflicts (last-write-wins for trip records).

Challenge: Accurate Fuel Cost per Trip

Fuel cost can't be assigned to a single trip — a tank fill covers many trips.

Solution: Calculate a rolling fuel cost per km using the last odometer reading, then apportion it to each trip based on its distance.

What I Learned

Offline-first architecture with sync queues is fundamentally different from always-online apps
Flutter's Riverpod makes it clean to derive complex calculations from primitive state
SQLite's better-sqlite3 is synchronous and blazing fast for simple single-user data
Building for a non-technical audience (delivery riders) means UI/UX has to be extremely simple and forgiving

RiderWatch - Riders Net Profit Watch App

Download APK: Google Drive · Mobile App Repo: RiderWatch

The Problem

RiderWatch solves this by giving riders a clear, real-time view of their true net profit.

Tech Stack

Layer	Technology
Mobile App	Flutter (Dart)
State Management	Riverpod
Backend API	Node.js, Express
Database	SQLite (via better-sqlite3)
Auth	JWT
Charts	fl_chart (Flutter)
Local Storage	SharedPreferences

Key Features

📊 Trip Tracking

Log each delivery trip: start/end time, distance, platform, earnings
Auto-calculate trip duration
Tag trips by platform (PickMe, Helago, Uber Eats, FoodPanda, etc.)

⛽ Expense Tracking

Log fuel fills: amount, price per litre, odometer reading
Automatic fuel efficiency calculation (km/l)
Other expense categories: maintenance, food, parking

💸 Net Profit Dashboard

Real-time net profit = Gross earnings − Fuel − Other expenses
Daily, weekly, and monthly breakdowns
Visual charts with trend analysis

🎯 Goal Setting

Set daily/monthly earnings targets
Progress bar showing how close you are to your goal
Alerts when on track vs. falling behind

📱 Offline-First

All data stored locally on-device
Syncs to backend when connected
Works fully offline — important for riders in low-signal areas

Architecture

Flutter App (Mobile)
│
│  HTTP/JSON (when online)
▼
Node.js / Express API
├── /auth          Login, refresh tokens
├── /trips         CRUD trip records
├── /expenses      CRUD expense records
└── /stats         Aggregated profit stats
│
▼
SQLite Database
(also mirrored locally in Flutter via SharedPreferences)

Flutter App Structure

lib/
├── main.dart
├── providers/
│   ├── auth_provider.dart
│   ├── trip_provider.dart
│   └── expense_provider.dart
├── screens/
│   ├── dashboard_screen.dart
│   ├── add_trip_screen.dart
│   ├── add_expense_screen.dart
│   └── stats_screen.dart
├── widgets/
│   ├── profit_card.dart
│   ├── trip_list_tile.dart
│   └── earnings_chart.dart
└── services/
    ├── api_service.dart
    └── local_storage_service.dart

Key Code: Net Profit Calculation

// providers/trip_provider.dart
@riverpod
class TripNotifier extends _$TripNotifier {
  @override
  List<Trip> build() => [];

  double get totalEarnings =>
    state.fold(0.0, (sum, t) => sum + t.earnings);

  double get totalFuelCost =>
    ref.read(expenseNotifierProvider)
       .where((e) => e.category == 'fuel')
       .fold(0.0, (sum, e) => sum + e.amount);

  double get netProfit => totalEarnings - totalFuelCost -
    ref.read(expenseNotifierProvider)
       .where((e) => e.category != 'fuel')
       .fold(0.0, (sum, e) => sum + e.amount);
}

Backend API (Node.js)

// routes/trips.js
router.get('/', authenticateToken, async (req, res) => {
  const { userId } = req.user;
  const { from, to } = req.query;

  const trips = db.prepare(`
    SELECT * FROM trips
    WHERE user_id = ?
      AND date BETWEEN ? AND ?
    ORDER BY date DESC
  `).all(userId, from ?? '2000-01-01', to ?? '2099-12-31');

  res.json({ success: true, data: trips });
});

router.post('/', authenticateToken, async (req, res) => {
  const { platform, earnings, distance, duration, date } = req.body;
  const { userId } = req.user;

  const result = db.prepare(`
    INSERT INTO trips (user_id, platform, earnings, distance, duration, date)
    VALUES (?, ?, ?, ?, ?, ?)
  `).run(userId, platform, earnings, distance, duration, date);

  res.status(201).json({ success: true, id: result.lastInsertRowid });
});

Database Schema

CREATE TABLE users (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  username TEXT UNIQUE NOT NULL,
  password_hash TEXT NOT NULL,
  created_at TEXT DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE trips (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  user_id INTEGER REFERENCES users(id),
  platform TEXT NOT NULL,
  earnings REAL NOT NULL,
  distance REAL,
  duration INTEGER,        -- minutes
  date TEXT NOT NULL,
  created_at TEXT DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE expenses (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  user_id INTEGER REFERENCES users(id),
  category TEXT NOT NULL,  -- fuel | maintenance | food | other
  amount REAL NOT NULL,
  note TEXT,
  date TEXT NOT NULL,
  created_at TEXT DEFAULT CURRENT_TIMESTAMP
);

Challenges & Solutions

Challenge: Offline-First Sync

Riders often work in areas with poor connectivity. The app needed to work fully offline and sync data when back online.

Challenge: Accurate Fuel Cost per Trip

Fuel cost can't be assigned to a single trip — a tank fill covers many trips.

Solution: Calculate a rolling fuel cost per km using the last odometer reading, then apportion it to each trip based on its distance.

What I Learned

Offline-first architecture with sync queues is fundamentally different from always-online apps
Flutter's Riverpod makes it clean to derive complex calculations from primitive state
SQLite's better-sqlite3 is synchronous and blazing fast for simple single-user data
Building for a non-technical audience (delivery riders) means UI/UX has to be extremely simple and forgiving

Kavidu Hasaranga

RiderWatch - Riders Net Profit Watch App

The Problem

Tech Stack

Key Features

📊 Trip Tracking

⛽ Expense Tracking

💸 Net Profit Dashboard

🎯 Goal Setting

📱 Offline-First

Architecture

Flutter App Structure

Key Code: Net Profit Calculation

Backend API (Node.js)

Database Schema

Challenges & Solutions

Challenge: Offline-First Sync

Challenge: Accurate Fuel Cost per Trip

What I Learned

Screenshots

Kavidu Hasaranga

RiderWatch - Riders Net Profit Watch App

The Problem

Tech Stack

Key Features

📊 Trip Tracking

⛽ Expense Tracking

💸 Net Profit Dashboard

🎯 Goal Setting

📱 Offline-First

Architecture

Flutter App Structure

Key Code: Net Profit Calculation

Backend API (Node.js)

Database Schema

Challenges & Solutions

Challenge: Offline-First Sync

Challenge: Accurate Fuel Cost per Trip

What I Learned

Screenshots