KinPiggy
Money together.
Family budgeting that survives contact with a real family: two adults with different ideas about what “the grocery budget” means, a bank feed that arrives in a lump, and a teenager who should be able to log their own spending without seeing the mortgage.
iPhone · iOS 18 or later · English & Português
Buckets, not one long list of categories.
Most budgeting apps give you one flat list. KinPiggy gives you buckets — think cost centres: Home, Children, Car, Leisure — and assigns categories to them.
One name, two budgets, two answers.
The same category can live in more than one bucket and be budgeted separately in each. Fuel under Car is a household running cost; Fuel under Holiday is part of the trip.
A category can only be used inside a bucket it has been assigned to. That isn’t a UI convention — the database enforces it, so a stray import or a second device can’t file an expense somewhere that doesn’t make sense.
Two kinds of budget, tracked independently.
Monthly lines are the regular control: groceries, electricity, school fees. Annual envelopes are for lumpy spending — car servicing, holidays, the dentist — where a monthly figure is a fiction.
A mismatch is usually information.
The two are deliberately not derived from each other. If your twelve monthly lines don’t add up to the annual envelope, KinPiggy tells you the gap instead of silently reconciling it.
Tap any row to see that category’s budget in that bucket across time — every month you’ve set, what was actually spent in each, and the envelope alongside. Add a month, change one, or remove it entirely.
Removing a budget is not the same as setting it to zero. Zero is a deliberate cap of nothing and goes red the moment anything is spent. Removing it means the month simply isn’t budgeted. Both are things people mean, so both are possible.
How much is left?
The home screen answers the only question that matters mid-month — and how long it has to last.
Over budget, named
Anything over is called out by bucket and category with the amount you’re over — not a red bar you have to interpret.
Nothing derived
Monthly and annual stay independent, so a gap between them stays visible instead of being quietly absorbed.
The statement arrives. Filing it is the part that goes wrong.
Connect a bank through open banking, or import a CSV. Either way the statement arrives as a list of things to file — so filing gets the most help.
Suggestions from your own history. “Used 2 times before” beats a guess from a merchant-name database that has never seen your bank.
Splits. One supermarket trip can be groceries and children’s clothes, in whatever proportion. The parts can never add up to more than the transaction, and anything still unaccounted for stays on the list as partly filed rather than quietly disappearing.
No duplicates. If you already logged the expense by hand, the bank row is linked to it rather than posted a second time. Imports are de-duplicated on the way in, so re-importing an overlapping CSV doesn’t double your spending.
Permissions built for a household.
Two separate ideas, because families need both. Role decides account-wide capability. Scope decides where.
| Role | Bank & imports | Budgets | Log spending |
|---|---|---|---|
| Ownerthe person who pays | Yes | Yes | Yes |
| Admin | No | Yes | Yes |
| Member | No | No | Yes |
Scope then decides where: each member gets access per bucket, or per category within a bucket, at one of three levels — view, contribute, or manage.
A teenager can log spending in Children · Clothes without ever seeing the mortgage.
Only admins ever see the full bank statement. Every one of these rules is enforced in the database, not just hidden in the app — a member’s device physically cannot fetch data they don’t have scope for.
Categories are yours.
Start from a catalogue of 61 ready-made categories, then make them your own: create, rename, re-icon, recolour, archive.
The list shows which buckets each category appears in — or “in no bucket”, because a category nothing points at can’t receive an expense, and that’s better said than discovered later.
Merge two categories when you realise Supermarket and Groceries were always the same thing. Everything moves — expenses, budgets, rules, member permissions — and budgets for the same month are added together rather than one overwriting the other.
Delete a category and its expenses aren’t deleted with it. They move to a holding category so your totals stay correct, and you’re told exactly what will move before you confirm. Or archive it instead, and the history stays filed under the name you used at the time.
Money, properly.
Arithmetic in every money field
Type 47.90*3 or 120-15 and it resolves. Splitting a bill shouldn’t require a second app. Try it:
Rates frozen, decimals exact
Each family picks a base currency; expenses can be logged in any currency. The exchange rate is frozen onto the expense when it’s posted, so last March’s numbers never move because today’s rate did.
Amounts are stored and totalled as exact decimals, never floating point — the way an accountant would expect.
In your language.
English and Brazilian Portuguese today, and the app follows your phone. Everything is translated — including how numbers and dates are written, which is where most apps stop trying.
Your starting categories are created in your language, and from that moment they’re your data: rename one and no update will ever overwrite it.
Switch the app’s language later and KinPiggy offers to rename the ones you never touched, telling you how many that is and leaving the rest alone.
Privacy, and who pays.
One payer per family. The account owner subscribes; everyone they invite uses KinPiggy at no cost. No per-seat pricing for your own household.
Bank access is read-only
KinPiggy connects through a regulated open banking provider and can see transactions. It cannot move money.
Your credentials stay yours
No bank credentials ever reach KinPiggy — you authenticate with your bank, not with us.
Consent expires, history doesn’t
Open banking consent runs 90 days by law. KinPiggy warns you before it lapses and keeps every transaction it already imported.
Losing your history because a consent expired would be indefensible.