A full money manager in 14MB. The budgeting apps are 150.

I noticed this by accident, checking my own App Store listing. Thrive downloads at about 14MB. I looked up the apps I get compared to, on the same day, from the same place.

I say “compared to” because Thrive is not just a budgeting app. It runs a household’s whole money picture — budget, emergency fund, giving, sinking funds, education savings, retirement, mortgage, credit cards. Most of the apps below do a narrower job than that, and every one of them is bigger.

Copilot is twenty times the size of Thrive. EveryDollar is twelve times. They are not doing twenty or twelve times as much — if anything, Thrive covers more ground. What we are all doing, is showing you your money and helping you decide what to do with it.

So where does the weight go?

What I can tell you for certain

I can only speak for Thrive, so let me start there. Thrive has zero third-party packages. Not few. None.

Every framework it uses is one Apple already ships inside iOS and macOS: SwiftUI to draw it, Core Data to store it, Charts for the graphs, PDFKit and Vision to read your statements, StoreKit for the subscription, Keychain to hold your email password, CloudKit to sync between your own devices. Those cost nothing to include, because they are already on your phone.

That is the whole app. There is nothing else in there.

What tends to make an app heavy

I have not taken anyone else’s app apart and I am not going to guess at what is in theirs. But the things that add tens of megabytes to a mobile app are well known, and there are only a handful of them:

A bank connection. No app builds its own pipe to twelve thousand banks. It pays a middleman — Plaid is the one you have probably seen — and the middleman supplies a ready-made slab of code to bundle inside the app. That slab carries the sign-in screen for every bank it supports, plus a small built-in browser to display them. All of it downloads to your phone whether you link ten banks or none.

Analytics. Code that watches which screens you open, how long you stay and where you give up, then reports it back. Session recording, funnel tracking, product analytics — each one a separate library, and apps commonly carry several at once.

Attribution and advertising. Working out which ad made you install the app is its own piece of bundled code, phoning an ad network to claim credit for you.

A cross-platform runtime. An app written once and run on both iPhone and Android has to carry the engine that translates it — a large fixed cost before a single feature is written.

Crash reporting, feature switches, in-app messages, support chat. All reasonable things to want. All code shipped to your phone, doing jobs for the company rather than for you.

Add those up and 150MB stops being mysterious. Almost none of it is budgeting.

The infrastructure is already on your phone

“It’s small because it does less” would be the fair objection, so here is what fits inside those 14 megabytes.

Thrive does zero-based budgeting with sinking funds and an emergency fund that models its own interest. It reconciles credit card payments made from checking. It tracks giving, education savings targets, retirement accounts and mortgages, runs scenarios against your goals, and keeps a household in sync across Mac and iPhone.

It also reads your bank and brokerage statements — a CSV, a PDF, or a screenshot from your phone — and sorts the transactions into your categories. Read that sentence carefully, because it is the one people assume is hiding something. The statement is read on your device, by your device. The file is never uploaded, never copied anywhere, and never kept by me. Thrive pulls the numbers out, puts them in your budget, and the file stays exactly where it was — in your downloads folder, in your camera roll, yours.

There is nowhere for it to go, which is the important part. Thrive has no server. I do not run one. There is no account to create, no database with your name in it, and no copy of your finances anywhere I could look at, lose, or be asked to turn over. What syncs between your Mac and your iPhone goes through your own private iCloud, under your Apple Account, which I have no access to either — encrypted in transit and at rest by Apple, in a place where I am not a party. If you connect an email account so Thrive can spot receipts, the password goes straight into your device’s Keychain, marked device-only so it never leaves for iCloud, and the mail connection itself is encrypted end to end.

The statement reading is also the part that surprises people technically. Recognizing text in a photograph of a bank statement sounds like the heaviest thing in the app, and in a different app it would be — you would bundle a machine learning model, or send the picture to a server and let it do the work. Apple already ships that model inside iOS and macOS. I ask the operating system, on your device, and I ship nothing.

That is the pattern throughout. The features are not missing. The machinery underneath them is just already on your phone, and reaching for it happens to be the private option as well as the small one.

Size is a receipt

I am not claiming a small app is automatically a good one. Plenty of excellent software is large, and some of that weight buys real features I have chosen not to build.

But download size is one of the few things about an app you can see from the outside without taking anyone’s word for it. It is a rough measure of how much is happening in there that is not the thing you opened the app to do. An app that talks to your bank, to an analytics service, to an attribution network and to an ad platform is carrying the code for all four conversations, and you are storing it.

Thrive is 14MB because it has no bank connection to make, nobody to report your behavior to, and nothing to attribute. There is no server for it to phone. Take all of that out and what is left is the money manager itself — which, it turns out, is the small part.

What it means on your phone

Less than you might hope, honestly. Storage is cheap and 150MB will not fill a modern phone. The practical difference is smaller than the number suggests.

The reason I think it is worth writing down is different. The weight is evidence. It is hard to advertise your way around a download that is twenty times larger than it needs to be for the job described on the listing, and it is one of the very few signals a customer can check for themselves before installing anything.

Next time you are choosing an app that will hold something private, look at its size first. It will not tell you everything. It will tell you something.

See how Thrive works →