← Projects|Mobile AppAndroidOffline-first

02 — Case study

LendTracker

A mobile application for tracking money lent, borrowed, repayments, and outstanding balances between people — built with React Native and Expo.

React NativeExpoReact Native PaperAsyncStorageAndroid

Dashboard

Total Lent

₹4,200

Total Borrowed

₹1,500

Net Pending

₹2,700

Rahul

lent

₹1,000

pending

Priya

lent

₹2,000

partial

Amit

borrowed

₹1,500

pending

Overview

LendTracker is an Android mobile application I built to solve a personal problem: keeping track of money lent and borrowed between people. The app provides a clean dashboard, manages lending and borrowing records, handles partial and full repayments, and works entirely offline.

Problem

Tracking informal loans between friends and contacts is messy — amounts get forgotten, repayments are partial, and balances go unreconciled. Existing finance apps are overkill; most people just need a simple, offline-first tracker.

Solution

Built a focused React Native app that tracks lending records, borrowing records, and transactions per contact. The data lives on-device using AsyncStorage for fast, offline access without requiring any account or server.

Architecture

How it's built

React Native (Expo)
React Native Paper UI
AsyncStorage
Local Device Storage

The app is fully offline — all data is persisted locally using AsyncStorage. No server, no account required. React Native Paper provides the UI component layer.

Features

What it does

Dashboard

Overview of total lent, total borrowed, and net pending balances at a glance.

Lending records

Log money lent to a contact with amount, date, and notes.

Borrowing records

Log money borrowed from a contact with full context.

Partial & full repayments

Record partial repayments over time or mark a debt as fully settled.

Transaction history

Full history of transactions per contact — lent, borrowed, and repaid.

Offline-first

All data stored locally on the device — works without internet access.

Offline-first

No server. No account. Just works.

All data is stored on the device using AsyncStorage. The app works without an internet connection — no account creation, no sync, no privacy concerns. Open it, track your money, close it.

Engineering

Key decisions

React Native + Expo

Expo simplifies the build and development workflow for Android targets, removing the need for native toolchain configuration.

AsyncStorage for persistence

Chosen for its simplicity and offline-first nature — no server, no auth, just local data that works immediately.

React Native Paper

Provides a consistent Material Design component library that suits a financial tracking context.

Stack

Technology roles

React Native

Cross-platform mobile framework for the Android app.

Expo

Build toolchain and development environment for React Native.

AsyncStorage

On-device persistence layer for all lending and borrowing data.

React Native Paper

Material Design UI component library for the app interface.

Result

A working Android application for offline tracking of lent and borrowed money between contacts, with full repayment history and running balance calculation.

Next project

03

ExDevX Agency Platform

Full-stack agency web platform built for ExDevX — a software development agency working across web, mobile, AI, and SaaS products.