The numbers add up
What is billed, what is paid and what is outstanding are computed from the documents themselves, and the reports say which way round the arithmetic went.
Android app · Clearbook
Send an invoice,
not a login.
Invoicing that keeps its arithmetic honest, on or off the network.
- No account, and no internet permission at all
- Invoices, customers and a catalogue, on the device
- Exported to CSV and PDF whenever you want it
Requires Android 8.0 (API 26) or newer.
NS
Northwind StudioVAT GB 123 4567 89
14 Mill Lane, Bristol
INV-2026-000414 Mill Lane, Bristol
BILL TOAcme Ltdaccounts@acme.example
ISSUED23 Oct 2026DUE6 Nov 2026
DESCRIPTIONQTYAMOUNT
Website redesign1£250.00
Net£250.00
VAT 20%£50.00
Total due£300.00
PAID · £300.00
Payment by bank transfer · Net 14 · Thank you.
The register
Every invoice,
one calm view.
Billed, collected and outstanding are computed from the documents, never typed into a second ledger. Each currency is kept apart.
CLIENTDOCUMENTSTATUSAMOUNT
Acme LtdINV-2026-0004Open£300.00
SKK EnterpriseINV-2026-0003Paid£0.00
Acme LtdINV-2026-0002Paid£300.00
Acme LtdINV-2026-0001Paid£250.00
BILLED£1,100.00
COLLECTED£550.00
OUTSTANDING£300.00
Collection rate 83% · still to collect this quarter
The practice
A catalogue, not a re-typed list
Products and services are entered once and reused, so a line on an invoice is a choice rather than a retype.
Customers, and their history
Every customer keeps their own record. Archiving one hides it from the list and leaves every invoice already sent to them exactly as it was.
Works where the signal does not
A van in a basement, a site with no bar of signal. The app has no internet permission, so it does not stop working because the network did.
PDF, and a spreadsheet
Invoices export as PDF and the books export as CSV, with a frozen column order, so a spreadsheet can be relied on rather than re-checked.
Nothing is deleted behind your back
A row is never quietly removed. The history is append-only, so a total can always be explained.
Private by default
The books stay
on the desk.
InvoiceFlow does not ask you to create an account, does not show advertising, and does not include analytics or crash-reporting services. Your data stays on your device unless you deliberately use a feature that sends it somewhere.
No account, no server copy, no analytics. Your clients and their invoices are rows in a local database, and the PDF is a file you choose to share.
Read the privacy policy →On Google Play
Open the book.
Send the first one.
Free to start. One optional purchase if you want the extras.
View on Google PlayRequires Android 8.0 (API 26) or newer.
Available on Google Play.