Travel Alarm – Smart GPS Travel Alert App

Overview

Travel Alarm is a GPS-based mobile application that alerts users before they reach their destination while traveling by bus, train, or taxi. The application continuously tracks the user's location and triggers an alarm when the device enters a defined radius near the destination.

The goal of the project was to solve a common travel problem — missing stops during long journeys.

---

Problem

During long journeys, passengers often fall asleep or lose track of their location and miss their stop.

Most existing travel alarm apps have issues such as:

• High battery consumption
• No background tracking
• Unreliable alarms
• Internet dependency

---

Solution

Travel Alarm solves this problem using intelligent GPS tracking and edge-trigger alerts.

Users select their destination on a map and define an alert radius (for example 500 meters or 1 kilometer). The app continuously monitors the distance to the destination and triggers an alarm when the user enters the defined radius.

The alarm works even if:

• The screen is off
• The app is in the background
• The phone is locked

---

Key Features

• Destination selection using map interface
• Custom alert radius configuration
• Real-time GPS tracking
• Background location tracking
• Loud alarm sound and vibration
• Lock screen notification controls
• Lightweight and battery-efficient
• Works without continuous internet connection

---

Architecture

The application follows a service-based architecture separating UI and core logic.

UI Layer

Handles only user interface and user interactions.

Screens:

• Home Screen
• Map Screen
• Tracking Screen

Service Layer

TrackingService

• GPS tracking
• Distance calculation
• Destination detection
• Background updates

AlarmService

• Play alarm sound
• Trigger vibration
• Show notifications
• Stop or control alarm

Device Layer

• Location API
• Audio manager
• Notification system
• Vibration hardware

This separation improves scalability, maintainability, and battery efficiency.

---

Tech Stack

Mobile Framework

• React Native (Expo)

Device APIs

• expo-location
• expo-notifications
• expo-av

Maps

• react-native-maps

Storage

• AsyncStorage

Build System

• EAS Build

---

Key Learnings

This project helped me learn:

• Mobile application architecture
• GPS and location tracking
• Background services in React Native
• Device API integration
• Building production-ready mobile apps
• Managing performance and battery optimization

---

Future Improvements

• iOS version
• Custom alarm tones
• Multiple saved destinations
• ETA prediction
• Smart battery optimization
• Google Maps routing integration