Android Native Kotlin

Expense Tracker App for Android

About this project

Expense Tracker is a modern Android app built with Kotlin and Jetpack Compose that helps users manage daily income and expenses. It works offline-first with local data storage, and syncs with Firebase Firestore for backup, restore, and multi-device access. Users sign in with Google and get a clean Material 3 interface with fast, responsive performance.

Objectives

Keep track of daily income and expenses in a simple app that works without internet, and never loses data when the phone is changed.

Key Features

  • Add income and expenses and view transaction history
  • Offline-first with local data storage
  • Firebase Firestore sync for backup and restore
  • Google Sign-In authentication
  • Clean Material 3 interface

Development Process

  1. Used AI for the design and project structure
  2. Built the app quickly with AI assistance
  3. Manually handled the Firebase setup, testing, and final adjustments

Challenges & Solutions

  • Working offline: Data is stored locally first, so the app stays usable without internet
  • Keeping devices in sync: Firestore sync backs up data and restores it on any device after sign-in

Technologies & Frameworks

Jetpack ComposeMaterial 3Firebase AuthenticationFirestore

Integrations & APIs

Firebase AuthenticationFirestoreGoogle Sign-In

Backend & Database

  • Local data storage on the device (offline-first)
  • Firebase Firestore for backup and cross-device sync
  • Firebase Authentication with Google Sign-In

Outcomes & Results

  • Working expense tracker with Google Sign-In and cloud sync
  • Open-source on GitHub

Need something similar?

Farhan Saeed · Available for new projects

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