About
Small business admin, made simple - by a small business
FullDiary is one app for the paperwork that eats a tradesperson's evenings: invoices and quotes written from a sentence, and a booking page and live diary for appointment businesses. It is built and run by Cynical Software Ltd, a UK company based in Perthshire, Scotland.
The AI writes; the code does the maths
Typing the job in a sentence is faster than any form, so the AI turns your words into a document. Every number on it - VAT, discounts, totals - is calculated by ordinary code in exact pence. An invoice cannot be wrong because a model guessed.
One simple price, no commission, ever
Booking apps that take a cut of every appointment grow when you grow and never stop. FullDiary is a free plan that is a real plan rather than a trial, or Pro at 9.99 GBP a month a person that never goes above 39.99 GBP, however big the team.
Your data is yours
Hosted in the EU, never used to train AI models, card payments handled entirely by your own Stripe account. Anything uploaded without an account is deleted after 24 hours.
Plain English, everywhere
On the site, in the product, in every email a customer of yours receives with your name on it. No jargon, no exclamation marks, no dark patterns. If something is a Pro feature, the page says so.
Why it exists
Most small business software is built for offices: forms, dropdowns, a training video, a sales call. A plumber writing an invoice in the van at six o'clock does not want any of that. They want to say what they did and who it was for, and have the paperwork exist.
So FullDiary starts from the sentence. Type "Invoice John Smith 2400 for bathroom installation, due in 14 days" and the invoice is written, numbered and priced with the VAT worked out - or fill in the boxes if you would rather. The same idea runs through FullDiary: enter your services, prices and hours, share one link, and customers book themselves in.
It is a young product, built quickly and improved most weeks from what customers ask for. If something is missing, the contact page reaches the person who builds it.