Smart Daily Expense Tracker Application Using Kotlin

Abstract

Personal finance management plays a vital role in maintaining financial stability, yet many individuals fail to track their income and expenses regularly. Existing expense tracking methods such as manual records and spreadsheets are inefficient and error-prone. This paper presents the design and development of a mobile-based Expense Tracker Application using Kotlin for Android devices. The proposed system allows users to add income and expenses, categorize transactions, view transaction history, and calculate real-time balance using a local database. The application focuses on simplicity, offline functionality, and efficient data storage. Testing results indicate that the system performs accurately and provides a smooth user experience. The application aims to enhance financial awareness and assist users in effective budgeting and expense control.

Introduction

In the modern digital era, effective personal financial management has become increasingly important due to frequent daily transactions such as food, transportation, shopping, and entertainment expenses. Without proper tracking, individuals may struggle with overspending, poor budgeting, and lack of savings. Traditional methods like notebooks and spreadsheets require manual effort and are prone to errors.

To address these challenges, this paper proposes a mobile-based Expense Tracker Application developed using Kotlin for Android devices. The application provides a simple, user-friendly, and efficient solution for recording and managing daily income and expenses. By using a local database (Room/SQLite), the system supports offline functionality, ensuring accessibility without constant internet connectivity.

Objectives

The main objectives of the project are:

• To provide an easy way to record daily income and expenses

• To calculate and display total income, expenses, and remaining balance

• To categorize transactions for better organization

• To maintain complete transaction history

• To offer a clean and simple user interface

• To reduce errors associated with manual tracking

Problem Statement

Many individuals fail to maintain accurate financial records, resulting in overspending and poor financial awareness. Existing mobile applications are often complex, subscription-based, or dependent on internet connectivity. Therefore, there is a need for a lightweight, offline, and user-friendly expense tracking solution.

Methodology and System Design

The application follows a structured development approach:

1. Requirement Analysis – Identifying essential features such as transaction recording and balance summaries.

2. System Design – Dividing the app into modules: dashboard, transaction management, and data storage.

3. Implementation – Using Kotlin for logic, XML for UI design, and Room/SQLite for local storage.

4. Testing – Ensuring accuracy, smooth performance, and crash-free execution.

System Architecture

The system consists of three main layers:

• User Interface Layer – Dashboard, transaction list, add/edit screens

• Business Logic Layer – Handles calculations and validations

• Database Layer – Stores transaction data locally

Key Features

• Dashboard – Displays total balance, income, expenses, and recent transactions

• Add Transaction – Allows income/expense entry with category, date, and notes

• Transaction History – Shows all transactions with color indicators

• Transaction Details – Enables editing and deletion

• Currency Support – Indian Rupee (?)

Implementation Details

• Kotlin is used for its concise syntax, null safety, and strong Android support.

• The database includes fields such as transaction ID, title, amount, type, category, date/time, and notes.

Results

The application was successfully tested on Android devices. It accurately stored income and expense records, updated balances in real time, and operated smoothly without crashes. The system proved effective for daily financial management.

Advantages

• Simple and intuitive design

• Fast processing

• Fully offline functionality

• Helps improve budgeting habits

• Reduces manual calculation errors

Limitations

• No graphical expense analysis

• No bank synchronization

• Single-user support only

Future Enhancements

Potential improvements include:

• Graphical reports and charts

• Export to PDF/Excel

• Cloud backup using Firebase

• Multi-user login system

• Budget alerts and notifications

Overall, the proposed Expense Tracker Application provides a practical, lightweight, and offline soluti

Conclusion

The Expense Tracker Application developed using Kotlin provides an effective solution for managing personal finances. The application allows users to track income and expenses easily, analyze spending patterns, and improve budgeting habits. The system is simple, efficient, and suitable for everyday financial management. The project successfully meets its objectives and demonstrates the usefulness of mobile applications in personal finance tracking.

References

[1] Android Developers Documentation – Kotlin [2] Kotlin Official Documentation [3] SQLite and Room Database Documentation [4] Mobile Application Development Concepts [5] Research papers on expense tracking systems

Copyright

Copyright © 2026 Ayesha Yasin Attar, Rehan Sameer Mulla, Shravani Shivaji Bangar, Shital S. Salokhe. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.