Track what comes in, see where it goes.
A personal finance app for Android that records income and spending, explains the numbers back to you, and exports a report you can actually hand to someone.
Most expense apps stop at a list and a pie chart. This one does the arithmetic properly and then talks to you about it.
- Log spending in seconds — type
450 lunchand it parses the amount, direction and category. Or use the full form, or scan a bill. - A financial picture that is actually correct — every figure the app quotes is computed in Dart over your full history, not estimated.
- An assistant that has read your numbers — it gets an exact brief and is told never to invent a figure. It stays friendly, and gets direct when the data says you are overspending.
- Reports worth sharing — pick a period, read it in-app, export a designed multi-page PDF.
| Quick add | Natural-language entry: spent 500 on lunch, got 45k salary |
| Manual entry | Amount, title, category, date, account, income/expense |
| Editing | Change any field on a record without deleting and retyping it |
| Receipts | Attach a photo to any transaction, kept on the device |
| Bill scanning | On-device OCR (ML Kit) fills a reminder from a photo |
| Recurring expenses | Daily to yearly, with automatic catch-up on open |
| Bill reminders | Local notifications, and one tap to record the payment |
| Search and filters | By text, direction, period, category and four sort orders |
- Analytics — category donut, spending trend, per-category breakdown
- Reports — seven periods (last 7/30 days, month to date, last month, last 3 months, this year, all time), each compared against the equivalent preceding window
- PDF export — cover band, KPI tiles, category chart, transaction tables, observations and page furniture
- One-off income — flag a windfall so a single asset sale does not masquerade as a 99% savings rate
- Budgets — a monthly ceiling per category or across all spending, judged on pace rather than the running total, since 60% used on the 15th is fine and the same figure on the 5th is not
- Accounts — cash, bank, wallets and cards, each with an opening balance and its own running balance
- Transfers — moving your own money between accounts is recorded as a paired entry that changes both balances without counting as income or spending, so a Rs. 25,000 shuffle to savings does not appear as Rs. 25,000 of expenditure
- App lock — the device biometric or PIN, re-arming whenever the app is backgrounded
- CSV export — transactions and budgets out through the share sheet, quoted per RFC 4180 and with plain numeric amounts a spreadsheet can total
- Account deletion — erase every record and close the account from inside the app
- Currency — NPR, INR, USD, EUR or GBP; symbol and digit grouping only, because the app holds no exchange rate and will not invent one
The model never does arithmetic. FinancialInsightsService computes the exact
picture — totals, month-over-month difference, savings rate, burn rate,
runway, category deltas, upcoming commitments — and the model is handed
finished figures with instructions not to recalculate.
Its tone is chosen from those numbers rather than at random:
| Stance | When |
|---|---|
| Calm | Nothing notable |
| Encouraging | Healthy savings rate |
| Watchful | Thin savings, or a large category climbing |
| Strict | Spending above income, or a negative balance |
Strict is deliberately reserved for money genuinely going backwards, so it keeps its weight.
One vocabulary shared by every entry path. When the assistant proposes a
category it is resolved locally against your existing list — exact, then known
synonym, then close spelling — so Food - Restaurant and
Food - Miscellaneous land on the same category instead of splitting your
food spending in two. A genuinely new category requires confirmation.
Rename, merge and delete are available, plus a duplicate scan for vocabularies that already drifted.
| Categories | Tidy up duplicates | Report periods |
|---|---|---|
 |
 |
 |
| Recurring expense | Bill reminder | Empty state |
|---|---|---|
 |
 |
 |
- Flutter 3.44 or newer
- A Firebase project with Authentication (Email/Password + Google) and Cloud Firestore enabled
git clone https://github.com/Rupak321/Smart-Expense-Tracker.git
cd Smart-Expense-Tracker
flutter pub getRegister an Android app in your Firebase project and drop
google-services.json into android/app/. Then generate the options file:
dart pub global activate flutterfire_cli
flutterfire configureGoogle sign-in additionally needs your debug and release SHA-1/SHA-256
fingerprints registered in Firebase, or it fails with sign_in_failed.
The assistant needs a Groq API key. It is a compile-time define, so a build without it can never reach the API whatever you change at runtime.
Create dart_defines.json in the project root — it is gitignored:
{
"GROQ_API_KEY": "gsk_your_key_here",
"GROQ_MODEL": "openai/gpt-oss-20b"
}flutter run --dart-define-from-file=dart_defines.jsonEverything except the assistant's replies works without a key. Transactions, analytics, reminders, reports and the locally computed briefing are all plain Dart over your own data.
Models are retired periodically and a retired model returns an error rather than falling back.
llama-3.1-8b-instantandllama-3.3-70b-versatileshut down on 16 August 2026. Check Groq's deprecation page if the assistant reports its model is unavailable, and set a current one viaGROQ_MODEL.
lib/
├── core/
│ ├── categories/ matcher and icon registry
│ ├── components/ shared widgets
│ ├── models/ domain types
│ ├── parser/ natural-language transaction parsing
│ ├── theme/ design tokens, light and dark themes
│ └── utils/ money formatting
├── presentation/
│ ├── screens/ one file per screen
│ └── widgets/ screen-specific widgets
└── services/ Firestore, auth, insights, reports, assistant
Two conventions matter:
Computation is separate from presentation. FinancialInsightsService,
FinancialReportService and CategoryMatcher expose pure functions that take
their inputs as arguments, so the maths is tested without Firebase or network.
Design flows through tokens. AppTokens and the AppColorRoles extension
name every radius, spacing step and colour role. Cards read appCard rather
than colorScheme.surface, which is what keeps them visible against the page
in both themes.
flutter test273 tests, covering:
- Insights and report maths — totals over full history, month-over-month difference, savings rate, burn and runway, period filtering, previous-period comparison
- Category matching — exact, synonym and fuzzy resolution, direction awareness, merge direction, duplicate detection
- Money formatting — South Asian and western grouping, compact form, parsing round-trips, currency switching
- Budget pace — comfortable, tight, on-track-to-overspend and over
- Accounts and transfers — per-account balances, and that a transfer never reaches income, spending, a savings rate or a budget
- Transaction direction — that a stored expense stays an expense whatever words its title contains
- CSV escaping — commas, quotes and newlines inside free-text fields
- Layout — shared components rendered at 320px and the maximum text scale, failing on any overflow
- Savings goals
- Recurring income
- Nepali localisation, and Devanagari in exported PDFs
- Home-screen widget for quick add
- Splitting an expense between people
- A real application id and release signing key
Issues and pull requests are welcome. Please run flutter analyze and
flutter test before opening a PR.
No license has been chosen yet, which means default copyright applies and
others cannot legally reuse the code. Add a LICENSE file if you intend it to
be open source.