Keel vs Invoice Simple: Which Invoicing App Fits You?
Short answer: Invoice Simple is a cloud invoicing app that runs on the web, iOS, and Android, with a free entry tier and paid subscription levels above it. Keel is an iPhone app that keeps invoices, receipts, and mileage entirely on the device — no account, no cloud — with a one-time price for Pro. Choose Invoice Simple if you invoice from a desktop, carry Android, or want the vendor holding your backup. Choose Keel if you want your books off other people’s servers and off a monthly bill.
These two apps land in the same search results, and for good reason: both are aimed at the person who does the work and also does the paperwork. But they answer different questions. Invoice Simple answers “how do I send a professional invoice without thinking about it?” Keel answers “how do I keep a year of records nobody else holds a copy of?”
Those are not the same problem, and the right answer depends on which one is actually costing you money. If you are still mapping the category rather than picking between two names, the survey of apps built for 1099 workers covers more ground than any head-to-head. And if what you really need is a document that gets paid, what to include on an invoice matters more than which app produced it.
What does Invoice Simple actually do?
Invoice Simple is an invoicing product for small businesses and sole operators. You pick a template, add your logo, fill in line items, and send. The client gets an invoice that looks like it came from a company with an office.
Around that core it has grown a reasonable amount: estimates, an expense tracker with an in-app receipt scanner, expense reports over a date range, and online payments through card, PayPal, Venmo, and ACH, including deposits and partial payments. Higher tiers add signature capture, photos on documents, and review requests. It runs on the web and on both mobile platforms, and the records live in your account in the vendor’s cloud, which is what makes the same invoice appear on the laptop and the phone.
The pricing is freemium: a free entry level with a cap on how many invoices you can send in a month, then paid tiers that lift the cap. The caps and prices have changed more than once, so read them off Invoice Simple’s own pricing page rather than any comparison article, this one included.
Where is Invoice Simple genuinely better?
Several places, and they are not small.
The learning curve is close to zero. This is the thing Invoice Simple does better than almost anything else in the category. You install it and send your first invoice within minutes — no reading, no chart of accounts, no deciding what kind of business you are. For anyone still invoicing out of a notes app because real software felt like a project, that speed is the entire value.
You can actually try it before you commit. The free tier is not a countdown timer — you can send real invoices to real clients and learn whether the app fits your week before any money changes hands. A trial that expires in fourteen days does not tell you that; a capped free tier does.
Web and Android. Keel has no web interface and no Android version. If you do paperwork at a laptop, carry an Android phone, or need a partner seeing the same records from another device, Invoice Simple does something Keel structurally cannot. That is a hard stop, not a gap to work around.
Payments are inside the product. The client taps and pays by card, PayPal, Venmo, or ACH, and the status comes back to you. Keel puts a payment link and QR code on the PDF, but the money moves through whatever processor you already use and Keel does not watch it settle.
Your backup is somebody else’s job. Phone in a puddle, log in from a new device, everything is there. With Keel you have whatever you exported.
Where is Keel better?
Keel runs entirely on your iPhone. No account, no password, no bank connection, no server holding a copy. Its App Store privacy label reads “Data Not Collected” — a statement about how the app is built rather than a promise about how a company behaves. There is no cloud copy of your books to leak, subpoena, or lose in someone else’s breach. If you have not thought that trade-off through, on-device vs cloud bookkeeping is the argument in full.
Keel is also wider than an invoicing app. Alongside invoices as PDFs with your own numbering, logo, brand color, and a payment-link QR code, it does receipt reading on-device with Apple Intelligence, a mileage log, a Freeboard view of where the year stands, reports, an Accountant Pack, an append-only hash-chained ledger, and a one-file export of the whole year.
Invoice Simple has an expense tracker with receipt scanning too, so that is not the dividing line. The difference is where the photo gets processed and stored, and whether mileage lives in the same place. For someone who drives all week, invoices, receipts, and mileage in one app that never phones home is a different shape of tool than an invoicing app with expenses attached.
Then there is the money. Keel Free is $0 with unlimited invoices, receipts, and mileage entries — no monthly cap on how many invoices you send. Keel Pro is a one-time $249.99 Lifetime purchase, not a subscription.
How do Keel and Invoice Simple compare side by side?
| Invoice Simple | Keel | |
|---|---|---|
| Platforms | Web, iOS, Android | iPhone only |
| Where data lives | Vendor’s cloud | On your device |
| Account required | Yes | No |
| Pricing model | Free tier plus subscription tiers | Free; Pro $249.99 one-time |
| Invoices on the free tier | Capped per month — check current plans | Unlimited |
| Estimates and quotes | Yes | Not yet — in development |
| Receipt capture | Yes | Yes, on-device via Apple Intelligence |
| Mileage log | Check current plans | Yes |
| Card payments | Integrated | Payment link and QR on the PDF |
| Automatic backup | Yes, via the account | No — you export the file |
| Works offline | Limited | Fully |
| Year-end export | Expense reports by date range | One file for the whole year |
| Privacy label | Cloud account | ”Data Not Collected” |
Rows marked “check current plans” depend on the tier and change without announcement. Verify them on the vendor’s site, not here.
What can Keel not do?
Worth stating plainly, because a comparison that only lists strengths is an advertisement.
Keel does not create estimates or quotes yet — the feature is in development, and until it ships you are writing quotes somewhere else. It does not import transactions from a bank feed, so every expense is one you photographed or typed. It does not file your taxes or tell you what you owe. It does not manage a team. And it has no web interface, so if your books happen at a desk with a keyboard, Keel will feel like the wrong shape from day one.
If two or more of those are dealbreakers, the honest answer is that you are shopping in the wrong aisle, and Invoice Simple is a reasonable place to look.
Who is Invoice Simple the right tool for?
Picture someone specific. She cleans houses, she has an Android phone, and she does her paperwork on a laptop at the kitchen table on Sunday nights because that is when the kids are quiet. She wants the client to be able to pay by card from the invoice without a phone call, and she does not want to think about backups at all.
For her, Invoice Simple is the correct purchase and Keel is not an option — not because Keel is worse, but because it runs on neither her phone nor her laptop. Recommending it would waste her evening.
The same goes for anyone whose main friction is that invoicing feels heavy. If you invoice late because opening the app is a chore, buy the app that opens fastest. Invoice Simple solves that well.
Who is Keel the right tool for?
Keel fits the one-person business on an iPhone that has decided its financial records should not sit on somebody else’s server. You invoice from the truck or the job site, you capture receipts as you go, and you drive enough that mileage is real money rather than a rounding error.
It also fits if you have simply run out of patience with monthly software. One purchase for a tool you use for a decade is a different relationship than a recurring charge you keep meaning to review.
If that is you, Keel: Invoice Maker & Receipts is on the App Store. The free tier is not a trial and there is no account to create, so there is nothing to cancel if it does not suit you.
Frequently asked questions
Is Keel a drop-in replacement for Invoice Simple?
For invoicing on an iPhone, largely yes — branded PDF invoices, custom numbering, a payment-link QR code, and no monthly cap on how many you send. But Keel has no web version, no Android version, no cloud sync, and no built-in payment processing. If you rely on any of those today, switching means giving them up deliberately rather than discovering the gap later.
Which one is actually cheaper?
They are different shapes, so it depends on your horizon. Invoice Simple is freemium: free with a monthly invoice cap, then subscription tiers. Keel is free with unlimited invoices, receipts, and mileage, plus an optional one-time $249.99 Lifetime purchase for Pro. Over several years a single payment wins on arithmetic — but only if you never needed the web access you were declining to pay for.
Does Keel do estimates like Invoice Simple?
Not yet. Estimates are in development but not shipping. If your work starts with a written quote the client approves before you invoice, that gap is the whole decision for you right now, and Invoice Simple covers the step today. Some trades quote every job; others invoice after the fact. Be honest about which one you are.
What happens to my Keel records if I lose my phone?
Whatever you exported is what you have. Keel keeps everything on the device with no server copy, so there is no account to sign into from a new phone and no vendor who can restore your history. That is the direct cost of the privacy model, not a bug. Export the year’s file on a schedule and keep it somewhere you trust.
Can I run Keel on a computer or an Android phone?
No. Keel is iPhone-only with no web interface, because keeping the data on one device is the design rather than a limitation waiting to be fixed. Invoice Simple covers web, iOS, and Android. If you are mixed-platform, that single fact settles the comparison and you can stop reading here.
Does either one connect to my bank?
Keel does not, by design — no bank feed, no aggregator, nothing imported automatically. Every entry is one you made, which is genuine extra work in exchange for no third party holding read access to your accounts. If bank linking is the part you were unsure about either way, whether bank aggregators are safe covers how those connections actually work.
This article is general information. Feature sets and pricing change — check both vendors’ current pages before deciding.
Where Keel actually fits
Private and on-device, with a real tradeoff.
Against cloud, bank-connected tools: no account and nothing readable leaving the phone — but no automatic bank import, and Keel does not file for you. Pro is a one-time purchase, not a subscription.
On-device · No account · Data Not Collected