Monthly Shell — iPhone budget app, no bank login, no account
Monthly Shell

One number that matters.

Monthly Shell is a budgeting app that wants nothing from you. No bank login. No account. No ads. You type what you spend, it shows you what's free to spend — and every month starts clean.

How it works Why there's no bank login
Monthly Shell home screen: Balance above the month wheel

Your number, front and centre.

Balance is your income minus what you've spent and set aside. Not a bank balance. Not a projection you have to decode. One number, recalculated the moment you log something.

Balance
$412.86
In this month$2,140.00
Spent$1,318.42
Set aside$408.72

Three seconds to log.

Open, tap the amount, done. Add a tag if you feel like it — untagged is a perfectly good answer. Or point the camera at a receipt and let your phone read the amount. The photo never leaves your device.

Logging a $12 burger on the keypad

A coach that stays quiet.

The turtle speaks when something's genuinely worth knowing — a budget drifting, a bill that won't quite clear, a habit you might not have noticed. One message a day, maximum. Five voices, from warm to nearly silent. You can turn it off completely.

Coach tab: budget bars and the turtle's messages
Hype Gentle Plain Nudge None
The turtle coach

See where you're headed.

A calm line of your month: what came in, what went out, and where that leaves you. Scrub any day with a finger. No candlesticks, no jargon — it's your money, drawn simply.

Coach tab: money in, money out, and the month drawn as a line

Nothing red. Ever.

Going over budget is information, not a moral failing. Monthly Shell has no alarms, no streaks to break, and no shame anywhere in it.

Groceries$28.40 over
Coffee$14.75 left

Your data stays yours.

Everything lives in a file on your phone. There's no server to breach, nothing to sell, nobody watching. Export it all to CSV whenever you like. Delete the app and it's genuinely gone.

The one exception is Family Sync, and only if you switch it on: that sends one profile to your own iCloud, never to us. The full policy says exactly what that means.

shell.dblives on your phone
Export my dataCSV
Delete the appgenuinely gone
One number that matters.
Every month, a clean shell to live in.
How it works