budget-book

Project Overview

Budget Book is a budgeting tool that sets a budget first and then logs each day, aimed at people who want to control their fixed monthly spending. It turns daily, weekly, and monthly fixed costs into budget items and automatically estimates how much the month will cost, so writing down milk at 2 yuan a day yields 60 yuan for the month. The app is written in pure-native Android without a WebView, ships as a 61 KB APK, requests no permissions, and keeps all data on the local device.

Plan the month in advance, then just record the date, amount, and note for each entry.

Key Features

• Budget items: turn daily, weekly, or monthly fixed costs into items and auto-estimate the monthly total
• Two-level budget: categories carry icons and hold items, with the category total summed from its items
• Quick logging: an entry needs only a date, an amount, and a note, with no category to pick
• Monthly available amount: enter what you can spend this month and see the remaining amount update live
• Monthly reuse: the plan carries over every month while spending starts fresh each month
• View switching: one page switches between the plan view and the ledger view via the planned and spent tiles
• Export and import: export a JSON backup and import it back to restore your data
• Theme switching: light and dark themes follow the system or can be toggled manually

Target Audience

• Individuals who want to control monthly spending
• People who like budgeting ahead of time
• Users who prefer lightweight offline tools
• Android phone users who need simple bookkeeping

Quick Start

Install on an Android phone

1. Download the latest APK from Releases
2. Transfer the APK to your phone and tap it to install
3. If installation from unknown sources is blocked, allow it in system settings and retry

Use on a computer

1. Double-click index.html in the repository root
2. Open it with any modern browser, with no install or network needed

Use the web version on a phone

1. Double-click start-lan-server.bat and note the address printed in the window
2. Connect the phone to the same Wi-Fi and open that address in a browser

Core Advantages

• Tiny size: the APK is only 61 KB and launches as fast as a built-in app
• Zero permissions: no network, storage, or contacts access, cleared on uninstall
• Fully offline: all data stays on the device and is never uploaded
• Effortless estimates: daily and weekly items are converted to monthly costs by days in the month

System Requirements

Item	Requirement	Note
OS	Android 7.0 or later	The web version runs in any modern desktop browser
Package name	com.budgetbook.app	An overwriting install keeps your data
Size	About 61 KB	Native implementation without a WebView
Extra dependencies	None	Requests no permissions

Notes

• The web version and the APK store data separately, so use export and import to move data
• The phone-browser option requires the computer to stay on and keep the same IP
• Export a backup regularly to protect important data
• Uninstalling the APK also deletes the data stored inside it