✦  An app by Gabriele Bulfon

I.O.U. app icon

I.O.U.

Shared expenses for households and groups — without an account, without a cloud, without giving your data to anyone.

What it does See it

iOS · iPadOS · Android

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The app

Split what you share,
with people you trust

I.O.U. keeps a running tally of who paid what, for whom, and how much each person owes at the end of the month. Log an expense in a couple of taps — snap the receipt if you like, on-device OCR pulls the amount out for you — and I.O.U. does the rest: categories, balances, and a clean settle-up at the close of each period.

There is no account, no server, no cloud. Your devices find each other on Wi-Fi, or across the internet via encrypted peer-to-peer channels, and keep themselves in sync. Nothing about your expenses ever leaves the phones you've paired.

What it does

Simple to use,
serious about your data

01

No account, no cloud

Nothing to sign up for. Nothing sent to a company server. Your data lives on your phones and nowhere else.

02

Peer-to-peer sync

Devices pair with a QR code and sync directly — on your Wi-Fi at home, or across the internet via WebRTC.

03

End-to-end encrypted

Every sync payload is encrypted with a secret only your paired devices know. Public relays never see your numbers.

04

Snap-and-log

Attach a receipt photo and on-device OCR reads the amount for you. No image ever leaves your phone.

05

Automatic settle-up

See who owes whom at a glance. When the period closes, I.O.U. works out the minimum set of transfers to zero everyone out.

06

Free · Pro unlocks groups

Free forever for a single group. A one-time Pro purchase unlocks unlimited groups from a single install.

Screens

A look inside

Three glimpses of the app in daily use — a household group at work, the balances view, and how a single expense gets logged.

The group home screen, showing sync status, a cumulative-spend chart and recent expenses.
The group Home · chart · recent expenses
Debit and credit view, showing who is owed and who owes, and the settle-up transfers to zero everyone out.
Debit & credit Who owes whom · settle up
The new-expense screen, with receipt attachment, amount, currency, category, payer and split.
New expense Receipt · amount · split

Privacy

Your ledger, on your phones. Nowhere else.

I.O.U. has no user accounts, no advertising, and no analytics. There is no I.O.U. server to trust — because there is no I.O.U. server. Payloads travel end-to-end encrypted between the devices you paired with a QR code, and only those devices can read them.

Support

Questions? Something odd?

I.O.U. is a small app built by one person. If something isn't working, or you'd just like to say hello, the mailbox below reaches me directly.

Get in touch

Bug reports, feature ideas, install questions, or a note about how you're using the app — all welcome.

Replies from a real human · usually within a few days