Documentation

• 1: Overview
• 2: Getting Started
• 2.1: User Guide

1 - Overview

What is Expense Tracker Android?

Expense Tracker Android is a comprehensive mobile application built with Kotlin and modern Android development practices. It helps you manage your personal finances by tracking expenses, analyzing spending patterns, and providing insights through beautiful charts and reports.

Key Highlights

• Modern Architecture: Built with MVVM architecture, Room Database, and Hilt dependency injection
• Secure: PIN and biometric authentication to protect your financial data
• Flexible: Customizable categories, account types, and multi-currency support
• Portable: Export/import data in CSV or JSON formats
• Beautiful: Material Design 3 UI with Light, Dark, and System themes

Why Use Expense Tracker Android?

What is it good for?

• Personal Finance Management: Track daily expenses and understand spending habits
• Budget Planning: Analyze monthly and yearly spending patterns
• Data Portability: Export data for tax purposes or financial analysis
• Privacy-Focused: All data stored locally on your device with optional backup
• Multi-Device: Backup and restore functionality for easy device migration

Technical Benefits

• Offline-First: Works completely offline, no internet required
• Fast & Efficient: Room database with optimized queries
• Secure Storage: Encrypted SharedPreferences for sensitive data
• Modern Codebase: Kotlin Coroutines for smooth async operations
• Well-Tested: Unit tests and instrumentation tests included

What is it not good for?

• Multi-User Scenarios: Designed for single-user personal finance tracking
• Business Accounting: Not suitable for complex business accounting needs
• Real-Time Sync: No cloud sync (by design for privacy)
• Investment Tracking: Focused on expenses, not investment portfolio management

Technical Specifications

Core Features

📊 Expense Management

• Add, edit, delete, and search expenses
• Customizable categories and account types
• Quick expense entry interface

📈 Statistics & Analytics

• Monthly and yearly expense breakdowns
• Beautiful charts (MPAndroidChart)
• Spending pattern analysis

💾 Data Management

• CSV and JSON export/import
• Full backup and restore
• Settings preservation

🔐 Security

• PIN-based app lock
• Biometric authentication (fingerprint/face)
• Encrypted storage
• ProGuard code obfuscation

🎨 Customization

• Light, Dark, and System themes
• Multi-currency support (USD, EUR, GBP, INR)
• Custom categories and account types

Where should I go next?

• Getting Started: Set up your development environment and build the app
• Examples: See code examples and usage patterns
• Concepts: Understand the app architecture and design decisions
• Tasks: Learn how to perform common development tasks

2 - Getting Started

Download the App

Quick Start

Expense Tracker Android is designed to be intuitive and easy to use right from the first launch. No account creation or complex setup required!

First Steps

1. Install the App: Download and install Expense Tracker Android on your Android device (requires Android 8.0 or higher)
2. Launch: Open the app - you’ll see the Expenses screen showing the current month
3. Add Your First Expense: Tap the floating “+” button to add an expense
4. Explore: Navigate through the tabs to see Statistics and Settings

What’s Next?

• User Guide: Complete guide on using all features
• Overview: Learn about the app’s capabilities and architecture
• Concepts: Understand the core concepts behind the app

Key Features at a Glance

• 📊 Expense Tracking: Add, edit, and delete expenses with ease
• 📈 Statistics: View monthly and yearly spending analytics with charts
• 🔐 Security: Protect your data with PIN or biometric authentication
• 💾 Data Management: Export, import, backup, and restore your data
• 🎨 Customization: Themes, currencies, custom categories, and account types

System Requirements

• Android Version: 8.0 (API 26) or higher
• Storage: Minimal storage required (app size ~10-15 MB)
• Permissions: Storage access for export/import/backup features
• Optional: Biometric hardware for fingerprint/face unlock

Need Help?

Check out the User Guide for detailed instructions on using every feature of the app.

2.1 - User Guide

This guide will help you get started with Expense Tracker Android and make the most of its features.

Getting Started

First Launch

When you first launch the app, you’ll see the main Expenses screen showing your current month’s expenses. The app is ready to use immediately - no account creation or login required!

Main Features

1. Adding Expenses

To add a new expense:

1. Tap the floating action button (FAB) with the “+” icon at the bottom right

2. Fill in the expense details:

   • Title: Name of the expense (required)
   • Amount: Cost of the expense (required)
   • Category: Select from predefined or custom categories (required)
   • Account: Choose the payment method (Cash, Credit Card, Debit Card, etc.)
   • Date: Select the expense date (defaults to today, cannot be future date)
   • Notes: Add optional notes or description

3. Tap Save to add the expense

Tips:

• The currency symbol shown is based on your selected currency in Settings
• You can’t select future dates for expenses
• All fields except Notes are required

2. Viewing Expenses

The Expenses tab shows all your expenses for the selected month:

• Monthly Total: Displayed at the top in a card
• Expense List: Scrollable list showing each expense with:
  • Title and amount
  • Category icon with color
  • Date and account type
  • Optional notes

Navigation:

• Use left/right arrow buttons to switch between months
• Swipe left/right on the month name to quickly change months
• Tap the total card to see category breakdown
• The “Next Month” button is disabled when viewing the current month

3. Editing Expenses

To edit an existing expense:

1. Tap on any expense in the list
2. The Add Expense screen opens in edit mode
3. Modify any fields as needed
4. Tap Save to update

Delete Option:

• In edit mode, a Delete button appears
• Tap Delete and confirm to remove the expense permanently

4. Deleting Expenses

Two ways to delete:

Method 1: Swipe to Delete

1. Swipe left on any expense in the list
2. Confirm deletion in the dialog

Method 2: Edit Mode

1. Tap the expense to open edit mode
2. Tap the Delete button
3. Confirm deletion

5. Searching Expenses

To search for specific expenses:

1. Tap the search icon in the top toolbar
2. Enter your search term (searches title, category, account, and notes)
3. Tap Apply to filter results
4. Tap Clear to remove the search filter

6. Filtering by Date

Filter by Specific Day:

1. Tap the calendar icon in the toolbar
2. Select a specific date
3. View expenses for that day only
4. Tap the X button next to the date to clear the filter

Filter by Month:

• Use the arrow buttons or swipe to navigate months
• The app remembers your selected month

7. Statistics & Analytics

The Statistics tab provides visual insights into your spending:

Yearly View

• Bar chart showing total expenses for each month of the year
• Tap any bar to see that month’s details
• Year selector to view previous years
• Total yearly expense displayed

Monthly View

• Pie chart showing expense distribution by category
• Category breakdown with amounts and percentages
• Tap any category to see detailed expenses
• Month selector to navigate different months

Features:

• Color-coded categories for easy identification
• Interactive charts (tap to see details)
• Percentage breakdown by category
• Total monthly spending

8. Category Breakdown

Access from the Expenses tab by tapping the total amount card:

• View all categories with their totals
• See percentage of total spending per category
• Visual representation with category icons and colors
• Quickly identify your biggest spending categories

Settings & Customization

Access Settings from the bottom navigation bar.

Theme Settings

Choose your preferred theme:

• Light Mode: Bright, clean interface
• Dark Mode: OLED-friendly dark theme
• System Default: Follows your device’s theme setting

How to change:

1. Go to Settings
2. Tap the Theme dropdown
3. Select your preferred theme
4. Theme changes immediately

Currency Settings

Support for multiple currencies:

• USD ($) - US Dollar
• EUR (€) - Euro
• GBP (£) - British Pound
• INR (₹) - Indian Rupee

How to change:

1. Go to Settings
2. Tap the Currency dropdown
3. Select your currency
4. All amounts will display with the new currency symbol

Custom Categories

Create and manage your own expense categories:

Add New Category:

1. Go to Settings → Custom Categories section
2. Tap Add Category
3. Enter category name
4. Choose an icon from the grid
5. The icon color is automatically assigned
6. Tap Save

Edit Category Icon:

1. Tap the edit icon next to any category
2. Select a new icon from the grid
3. Icon and color update immediately

Delete Category:

1. Tap the delete icon next to any category
2. Confirm deletion
3. Existing expenses with this category remain unchanged

Default Categories:

• Food & Dining
• Transportation
• Shopping
• Entertainment
• Bills & Utilities
• Healthcare
• Education
• Travel
• Personal Care
• Others

Custom Account Types

Manage payment methods:

Add New Account:

1. Go to Settings → Custom Account Types section
2. Tap Add Account Type
3. Enter account name (e.g., “PayPal”, “Venmo”)
4. Tap Save

Delete Account:

1. Tap the delete icon next to any account
2. Confirm deletion

Default Accounts:

• Cash
• Credit Card
• Debit Card
• Bank Transfer
• Digital Wallet

App Lock & Security

Protect your financial data with PIN or biometric authentication:

Enable App Lock:

1. Go to Settings → Security section
2. Toggle Enable App Lock
3. Choose authentication method:
   • PIN: Set a 4+ digit PIN
   • Biometric: Use fingerprint or face unlock (if device supports)
4. Confirm your PIN

Change PIN:

1. Go to Settings → Security
2. Tap Change PIN
3. Enter current PIN
4. Enter and confirm new PIN

Disable App Lock:

1. Toggle off Enable App Lock
2. Enter your current PIN to confirm

Data Management

Export Data

Export your expenses for backup or analysis:

Export Formats:

• CSV: Spreadsheet format (Excel, Google Sheets)
• JSON: Structured data format

How to Export:

1. Go to Settings → Data Management section
2. Tap Export Data
3. Choose format (CSV or JSON)
4. Select save location
5. File is saved with timestamp in filename

CSV Export includes:

• Date, Title, Amount, Category, Account, Notes
• Compatible with Excel and Google Sheets
• Easy to analyze and create reports

Import Data

Import previously exported data:

How to Import:

1. Go to Settings → Data Management
2. Tap Import Data
3. Select the file to import (CSV or JSON)
4. Choose import mode:
   • Merge: Add to existing data
   • Replace: Clear existing data first
5. Confirm import

CSV Import Template

If you want to create your own CSV file for import, use this format:

CSV Header (Required):

ID,Title,Amount,Category,Account,Date,Notes,Created At

Example CSV File:

ID,Title,Amount,Category,Account,Date,Notes,Created At
1,"Grocery Shopping",45.50,"Food & Dining","Cash","2024-01-15 10:30:00","Weekly groceries","2024-01-15 10:30:00"
2,"Gas Station",60.00,"Transportation","Credit Card","2024-01-16 08:00:00","","2024-01-16 08:00:00"
3,"Movie Tickets",25.00,"Entertainment","Debit Card","2024-01-17 19:00:00","Weekend movie","2024-01-17 19:00:00"
4,"Electric Bill",120.00,"Bills & Utilities","Bank Transfer","2024-01-18 14:00:00","Monthly bill","2024-01-18 14:00:00"

Field Requirements:

• ID: Can be any number (will be auto-generated on import)
• Title: Required, text in quotes if contains commas
• Amount: Required, decimal number (no currency symbol)
• Category: Required, must match existing or custom category
• Account: Required, must match existing or custom account type
• Date: Required, format: YYYY-MM-DD HH:MM:SS
• Notes: Optional, empty string if no notes
• Created At: Required, format: YYYY-MM-DD HH:MM:SS

Tips for CSV Import:

• Use quotes around text fields that contain commas
• Date format must be exactly: YYYY-MM-DD HH:MM:SS
• Amount should be a number without currency symbols
• Empty notes should be represented as ""
• Save file with UTF-8 encoding for special characters

Backup & Restore

Create complete backups of your app data:

Create Backup:

1. Go to Settings → Data Management
2. Tap Backup Data
3. Choose save location
4. Backup file includes:
   • All expenses
   • Custom categories
   • Custom account types
   • App settings (theme, currency, etc.)

Restore from Backup:

1. Go to Settings → Data Management
2. Tap Restore Data
3. Select backup file
4. Confirm restoration
5. App restarts with restored data

Backup File Format:

• JSON format with .json extension
• Includes timestamp in filename
• Contains complete app state

Tips & Best Practices

Organizing Expenses

1. Use Consistent Categories: Stick to the same categories for similar expenses
2. Add Notes: Include details like store name, purpose, or people involved
3. Regular Entry: Add expenses daily to avoid forgetting
4. Review Monthly: Check your statistics at month-end

Managing Categories

1. Keep It Simple: Don’t create too many categories
2. Merge Similar: Combine related categories (e.g., “Groceries” and “Food”)
3. Use Icons Wisely: Choose recognizable icons for quick identification
4. Regular Cleanup: Delete unused categories periodically

Data Safety

1. Enable App Lock: Protect sensitive financial data
2. Regular Backups: Create monthly backups
3. Export Important Data: Keep CSV exports for tax purposes
4. Test Restores: Occasionally test backup restoration

Performance Tips

1. Archive Old Data: Export and delete very old expenses
2. Limit Search: Use specific search terms for faster results
3. Close Unused Tabs: Navigate away from Statistics when not needed

Troubleshooting

Common Issues

Expenses Not Showing:

• Check if you’re viewing the correct month
• Clear any active search filters
• Clear date filters (tap X button)
• Refresh by switching tabs

Can’t Add Expense:

• Ensure all required fields are filled
• Check that amount is a valid number
• Verify date is not in the future
• Try restarting the app

App Lock Not Working:

• Check biometric settings in device Settings
• Ensure PIN is correctly set
• Try disabling and re-enabling App Lock

Export/Import Fails:

• Check storage permissions
• Ensure sufficient storage space
• Verify file format (CSV or JSON)
• Try a different save location

Statistics Not Updating:

• Switch to another tab and back
• Pull down to refresh (if available)
• Restart the app

Getting Help

If you encounter issues:

1. Check this user guide
2. Review app settings
3. Try restarting the app
4. Create a backup before troubleshooting
5. Reinstall as last resort (will delete data)

Privacy & Data

• Local Storage: All data stored on your device
• No Cloud Sync: No automatic cloud backup (by design)
• No Tracking: App doesn’t collect usage data
• Encrypted Storage: Sensitive data encrypted
• Offline First: Works completely offline

Your financial data never leaves your device unless you explicitly export or backup to external storage.

Need more help? Check out the other documentation sections for detailed technical information.