Every group trip in India ends the same way. The photos are great, the memories are better, and then the WhatsApp group turns into an accounting nightmare.
"Who paid for the cab from the airport?" "I already sent you my share." "The spreadsheet formula broke again."
I'm a senior full-stack developer, and like most developers, I solve annoyances by building things. After one too many trips that ended in broken Google Sheets and awkward payment reminders, I built SettleUp — a free, INR-first expense splitting app for trips, flatmates, weddings and events. It's a passion project, built nights and weekends, and it's now live on the App Store (Android coming soon).
This post covers what SettleUp does, why exact rupee maths matters more than you'd think, and a peek at the engineering underneath.
The Problem With Splitting Expenses in a Group
Most groups handle shared costs in one of three ways, and all of them break down:
- Group chat memory — Someone posts "I paid ₹2,400 for dinner" and it scrolls away within an hour. Three weeks later, nobody remembers who was even at that dinner.
- Spreadsheets — They work until someone edits a formula, forgets a row, or the trip grows past ten expenses. Then the totals stop matching and nobody trusts the sheet anymore.
- Global split apps — Tools like Splitwise are solid, but most are dollar-first, ad-supported, and lock useful features behind a paywall. If you've ever seen a rupee amount rounded strangely because the app calculates in floating-point dollars, you know the frustration.
What Indian groups actually need is simple: a group expense tracker that's rupee-native, exact to the paise, free, and clear about who owes whom. That's the entire brief I built SettleUp around.
What SettleUp Does
SettleUp is a free bill split app with no ads and no hidden fees. The core loop takes minutes:
- Create a group — a trip, a flat, a wedding, an event — and invite friends by email. Nobody joins without accepting, so there are no awkward surprise adds.
- Add expenses — log who paid, who participated, pick a category, and choose how to split.
- See balances — the app instantly shows who owes whom across the whole group.
- Settle up — pay by UPI or cash, record it, and everyone's square.
You can also split one-to-one with a single friend, without creating a group — handy for that recurring "I'll get this one, you get the next" arrangement.
Four Ways to Split a Bill (Because Real Life Isn't Always ÷4)
Equal splits cover dinners and cabs, but rent, trips and events get messier. SettleUp supports four split modes:
| Split type | Best for | Example |
|---|---|---|
| Equal | Dinners, cabs, tickets | ₹1,200 ÷ 4 = ₹300 each |
| Exact amounts | Uneven shares | You ₹500 · Priya ₹300 · Rahul ₹400 |
| Percentage | Rent, utilities | 60% / 40% → ₹720 / ₹480 |
| Shares | Someone consumed more | 2:1:1 → ₹600 · ₹300 · ₹300 |
An expense can also have multiple payers — two friends splitting the hotel bill at checkout, combined with any split method for who owes what. Real bills are messy; the app is built for that.
The Feature I'm Most Proud Of: Smart Settle Up
Here's a scenario every group knows:
Saurabh owes Anuj ₹500. Anuj owes Chakresh ₹300. Chakresh owes Saurabh ₹100. Three payments, three UPI transfers, three chances for someone to forget.
Smart Settle Up nets everyone's balances and computes the minimum set of transfers needed to clear all debts — using a min-cash-flow algorithm — then records them in one tap. In this example, three tangled payments become two clean ones. On a real 8-person trip with dozens of expenses, a web of IOUs collapses into two or three transfers.
For the algorithmically curious: this is the classic minimum cash flow problem — greedily match the largest creditor with the largest debtor until every balance hits zero. Simple idea, disproportionately satisfying in practice.
Why Paise-Perfect Maths Matters
This is the engineering detail I care about most, and it's invisible when it works.
Most apps store money as floating-point numbers. Split ₹100 three ways in floats and you get 33.333... — and rounding those shares means the totals drift by a paisa here and there. Over dozens of expenses, the group total quietly stops summing to zero, and users lose trust in the numbers.
SettleUp calculates everything server-side in integer paise (₹1 = 100 paise) using the largest-remainder method to distribute rounding. The guarantee:
Group balances always sum to zero. What's owed always equals what's due. No drift, no "why does the app say ₹299.99?", no guesswork.
If you're building anything financial: never store money as floats. Integers in the smallest unit, always.
Budgets, Categories and Staying in Sync
Beyond splitting, SettleUp helps groups stay on top of spending:
- Group budgets — set a total or monthly budget with optional per-category caps, and watch a live "spent vs left" bar move from green to amber to red as expenses come in.
- Custom categories — Fuel, Rent, Gifts, or anything else, per group, with spending breakdowns.
- Live activity feed & push notifications — every expense, settlement and invite appears in one timeline, so nobody misses an update or disputes a charge later.
- Notes, comments & edit history — a full audit trail for every expense.
Privacy: No Ads, No Tracking, No Data Selling
SettleUp is free, and it will stay that way without ads. There's no data selling and no tracking — the app exists to split bills, not to monetise attention.
- Authentication uses JWT tokens with bcrypt-hashed passwords
- Sign in with email/password or phone OTP
- Delete your account anytime from the app or the website
I built this to solve my own problem. Keeping it clean and private was non-negotiable.
The Tech Stack (For Fellow Developers)
Since this is a passion project by a developer, for anyone curious:
- Mobile app: Flutter with Material Design 3
- Backend: Node.js + TypeScript
- Database: MongoDB
- Money maths: server-side, integer paise, largest-remainder method
- Auth: JWT + bcrypt, phone OTP support
Shipping it end-to-end — App Store review, privacy policy pages, email invite flows, push notifications — was a reminder that the last 10% of a product is 90% of the work. Every "small" feature like email invitations that just work hides a surprising amount of edge-case handling.
Frequently Asked Questions
Is SettleUp free?
Yes — completely free, with no ads and no hidden fees.
Is SettleUp an alternative to Splitwise in India?
That's the goal for Indian users: INR-first, paise-accurate, free, and ad-free. If you've found global split apps clunky with rupees, SettleUp was built for exactly that gap.
Which platforms does it support?
iPhone today via the App Store; Android is coming soon to Google Play.
Can I split with just one friend?
Yes — one-to-one splitting works without creating a group.
How accurate are the balances?
All calculations run server-side in integer paise. Group totals always sum to zero — mathematically guaranteed.
Can I use it for a wedding or event?
Absolutely. Create a group, track vendors, gifts and shared costs, and settle when it's done. Groups can even be reopened after settling.
Try It
SettleUp is live now at settleup.truelytech.com — download it from the App Store, take it on your next trip, and let the maths handle itself.
If you're a developer and want to talk about the min-cash-flow algorithm, Flutter, or the joys of App Store review, my inbox is open. This one was built purely for the love of building — and because no friendship should end over ₹600 and a broken spreadsheet.
Built with ❤️ in India. Free, no ads, paise-perfect.
