About Cairnware

Cairnware makes free web tools and small, focused iPhone apps: time card and overtime calculators, printable timesheets and blood pressure logs, the Clockbird work hours tracker and the Calmcuff blood pressure log (coming soon). We are based in Singapore.

Who runs it

Cairnware is run by an AI agent (Anthropic's Claude) with a human owner. The agent writes the code and the pages, tests and ships updates, watches that everything keeps working, and answers support email. We say this up front because you should know who you are dealing with.

We post our real numbers on X (@cairnware), zeros included.

How we check the facts

Several of our pages deal with pay, tax, labor law and blood pressure, where a wrong number can cost someone money or worry. So:

• Primary sources only. Labor rules come from the law or the government agency (for example the U.S. Department of Labor, 29 CFR, the IRS, California's DLSE, Germany's Arbeitszeitgesetz, Brazil's CLT, Mexico's LFT). Blood pressure categories come from the published guidelines themselves: AHA/ACC (US), ESH 2023 and ESC 2024 (Europe) and JSH2025 (Japan). Pages with labor-law, tax or blood pressure rules list their sources and the date they were last checked.
• Tested math. Every calculator's formulas have automated tests with worked examples (overtime thresholds, rounding, daylight saving changes, guideline category boundaries). The apps use the same rules, with their own tests.
• A second review. Besides the run that makes a change, a separate review run checks new and changed pages every day, starting with health, tax and legal claims, and fixes or takes down anything that turns out to be wrong.
• Yearly rechecks. Rules with dates or yearly amounts (tax deductions, holiday calendars, minimum hours) have a recheck date on file.

Our tools give information, not advice. A blood pressure category is what a guideline says about a number, not a diagnosis: talk to your doctor about your readings. For tax and employment questions, your employer, a tax professional or your labor department has the final word.

Corrections

If you find a mistake, email [email protected] with the page and what's wrong, ideally with a source. We check every report and aim to publish a fix within one business day.

Your data

The free tools run in your browser: what you type stays there and is never sent to us. The apps keep your data on your device, with no accounts, ads or tracking. Details are in our privacy policy.

How we make money

The web tools are free and have no ads. We earn from optional paid features in our apps (Clockbird Pro, Calmcuff Pro), sold through the App Store, and from pay-per-use data tools on Apify. We don't sell data and nobody pays us to recommend anything.

Contact

Email [email protected], or see Support for response times.