Opportunities › Privacy-first personal bookkeeping across devices › Proposed app
Keelbook
Private bookkeeping that syncs through storage you choose
- Score
- 45
- confidence 51
- Evidence
- 6
- items on the page
- Rivals
- 2
- named in sources
- First version
- 35 d
- estimate
- Type
- Mobile app
- PWA: installs on iPhone and Android
- Market since
- 2009
- Mature market · AI estimate
ScreensConcept
Mobile app: Users quickly capture expenses from receipts and text while away from a desk; the app's quick-entry design fits mobile use on the go. Sample screens on a phone, in the proposed brand. Their numbers are sample data.
Quick add
¥32.00
- Notenoodles lunch
- CategoryFood
- DateToday
- AccountCash
About this appAI proposal
Keelbook is a personal bookkeeping app that keeps your ledger on your own devices. Entries are saved locally first and work offline. To use several devices, you pick where the synced copy lives: your own server, iCloud, a WebDAV folder or an S3 bucket.
It is for people who track daily spending and do not want a company holding their financial history. Type a short note like 'noodles 32 lunch' or photograph a receipt, and the app drafts the entry for you to confirm.
There is no account with us that holds your data. Sync files are encrypted on your device before they leave it, and you can export everything to plain CSV at any time.
- Tagline
- Your money ledger, kept in your own hands.
- Voice
- calmplaintrustworthy
- Why this name
- A keel keeps a boat steady and belongs to the boat, like a ledger that stays with you. Keelbook joins it with the old word for an account book.
In the first version
Members say which features they would use. It tells PWAS what people want; it changes no score.
Local-first ledger
Every entry is saved on the device first. Add, edit and search offline with no sign-in.
No member yet
Choose where sync lives
Sync through your own server, iCloud, WebDAV or S3. Switch later without losing history.
No member yet
Encrypted before it leaves
Sync files are encrypted with a key only you hold. The storage host sees only ciphertext.
No member yet
Quick capture from text or receipt
Type a note or photograph a receipt. Amount, category and date are drafted for you to confirm.
No member yet
Brand identityAI proposal
Check the name against trademark registers before using it.
Palette
#14535ADeep Teal · primary#F7F3EAPaper · surface#1E2326Ink · text#E0692FPersimmon · accent#8FB59ESage · data
Typography
Aa
Keelbook
ABCDEFGHIJKLMNOPQRSTUVWXYZ 0123456789
Your money ledger, kept in your own hands.
PricingAI proposal
The material gives no competitor prices. These tiers are a starting point to test, built on the opportunity's freemium idea.
Free
Free
- Local ledger on unlimited devices
- Manual entry and CSV export
- Sync via WebDAV or S3 you provide
Plus
$3 a month
- Text and receipt capture
- iCloud and own-server sync guides
- Extended history and budgets
Plus yearly
$29 a year
- Everything in Plus
- Two months free
Would you pay Plus yearly · $29 a year?
Your answer tells PWAS which prices people accept. It changes no score.
No answers yet.
What it could be worthEstimate
What a software business making this much sells for today, from real deals. Pick a monthly revenue.
If it makes
Worth about
$194,000
Sale range $132,000 to $263,000
$120,000 a year in revenue
From 87 software businesses listed and sold on Empire Flippers in the last year, revenue vetted by the broker: they sell for about 19× their monthly revenue, most between 13× and 26×.
Measured on profit, the middle deal is 32× monthly net profit: about 2.7 years of profit.
An estimate, not an offer or financial advice. A real price depends on profit, growth, churn, how much of the work is the owner's, and the buyer.
How it would growAI proposal
How the product would reach new customers through its own use, and how the first ones would be found. A plan to test, not a result.
- Built-in loop
- No loop in the product. Keelbook works on a person's own ledger and shares nothing by default. It reaches customers through content, self-hosting communities and word of mouth.
- Do they become customers?
- Test whether privacy-minded users from self-hosting and open-source communities convert from free to Plus when capture is the paid feature.
- First customers
- Individuals who already self-host or use WebDAV or S3 and track personal spending, starting with Chinese-speaking users.
- Where to reach them
- GitHub and self-hosting forums: Post setup guides and a comparison with local-first bookkeeping projects in relevant communities.
- Privacy communities: Share how encrypted sync works and offer early access to people who ask for it.
- First milestone
- Fifty weekly active users syncing across two devices and ten paying for Plus within 90 days.
Why people already pay for this
- VerifiedGitHub repository gained 2529 stars in 400 days
- AI inferenceMarket exists for personal bookkeeping apps: the repository has significant adoption with 2,529 GitHub stars and 344 forks, indicating developer and user interest.
- Public claimUsers want local-first and privacy-preserving alternatives to cloud personal finance platforms.
- AI inferenceAI expense capture is a key feature demand, reducing manual data entry burden.
- Public claim
Tech stack
Every proposal builds on the same PWA base, installable from the browser on any phone or computer. Dashed boxes are what this app adds.
- AppNext.js and TypeScript
- PWAManifest and service worker
- UITailwind CSS
- Data and authSupabase Postgres
- PaymentsStripe
- EmailResend
- HostingVercel
- This app · Local storageIndexedDB with a local SQL layerThe ledger lives on the device and must work offline.
- This app · EncryptionWeb Crypto, client-side keysSync files are encrypted before upload; no plain data on the host.
RisksAI inference
- TechnicalMerging edits from several devices through plain file storage can create conflicts or duplicates. It needs a careful, well-tested merge design.
- PlatformPWA storage on iOS can be cleared by the system and iCloud access from a web app is limited, so some sync options may need workarounds.
- AIOn-device receipt reading may be less accurate than cloud models, especially for Chinese receipts, and heavy models may be slow on older phones.
- CommercialAn open-source alternative already draws interest (2,529 GitHub stars). Free self-hosters may not pay for a paid tier.
- DataIf users lose their encryption key, we cannot recover their ledger. Key backup needs clear handling.
Everything marked AI proposal or AI inference was written by a model from the evidence on the opportunity page. The proposed name must be checked against trademark registers before it is used.