Fraction Feet Inch Calculator — Privacy policy

Effective date: 2026-10-06

Fraction Feet Inch Calculator is made by KLM Labs. On your Home Screen it appears as Construction Calculator. It does feet, inch and fraction math and construction calculations on your iPhone. This policy explains what stays on your device, what leaves it, who receives it and why.

The short version

Your calculations are stored on your device. Numbers you type, answers, your history tape, tool inputs and the Home Screen widget's last answer are stored on your iPhone, and the app never sends them to us or to analytics.
There is no account and no sign-up. The app never asks for your name or email address. Your usage and purchase records are kept together by random identifiers, so they are linked to you (see below).
Usage analytics with a random identifier. The App Store version sends usage events, such as "a tool was opened", to PostHog, together with technical details about the app and device. An approximate location (country and city) is worked out from your internet address, which PostHog does not store. No calculation, input or answer is ever included.
Purchases are handled by Apple. We never see your card or bank details. RevenueCat receives your App Store purchase records so the app can unlock and restore your plan.
No ads and no tracking. We do not sell data, show adverts, use an advertising identifier, or track you across other apps and websites.

What is stored on your device

Everything you enter and calculate is stored on your iPhone: the numbers and expressions you type, answers, memory, the history tape, your precision and other settings, the last inputs of each tool, and the last answer shown by the Home Screen widget. The app and its widget share that last answer through storage on your iPhone. The app never sends any of it to KLM Labs, PostHog or RevenueCat, and we cannot see, retrieve or delete it. It leaves your iPhone only if you share it: you can share your history or a single line, copy an answer into another app, or share a stair layout PDF. Like other app data, it is included in your iPhone's backups (iCloud Backup or a computer backup) if you have backups turned on; those backups are controlled by Apple and your settings, not by us.

The calculator and tools work offline. Copy and paste use your iPhone's clipboard only when you choose Copy or Paste.

Product analytics (PostHog)

We use product analytics to learn which features are used and where people get stuck, so we can improve the app. PostHog, Inc. processes the analytics for KLM Labs on servers in the United States. Analytics are sent only by the App Store version of the app (and TestFlight test builds); there is no analytics setting in the app.

What analytics collects

Events describing what you did, never what you calculated. The app sends these events: the app was opened; a calculation was completed; a tool was opened (which tool); a result was sent from a tool to the calculator (which tool); a stair layout PDF was shared; a guide was opened (which guide); the app was opened from the widget (which shortcut); the free-trial reminder page was shown, and whether you allowed notifications; the plans screen was shown (where it was opened from and which set of plans it showed); and the result of a purchase or restore (which plan, Yearly or Lifetime, whether a free trial started, and whether it completed, was cancelled, failed or is waiting for approval). No event ever contains a number, an expression, an input or an answer from a calculation.

Technical details that the analytics software adds to each event: the app's name, version and build; the device maker, model and type; the iOS version; the screen size; your language, region and time zone settings; whether the device is on Wi-Fi or cellular data; whether the app came from TestFlight; the analytics software's name and version; the time of the event; and random event and session identifiers. They also include the app's bundle identifier, the operating system's name, the generic device name iOS reports (such as "iPhone"), and whether the app is running in a simulator or was installed from outside the App Store.

A random identifier that PostHog creates on your device. It lets PostHog count events from the same installation. It is not your name, email, phone number, Apple Account or the device's advertising identifier. The app also gives it to RevenueCat, so your usage and purchases can be matched (see below).

An approximate location. Like any internet service, PostHog sees the IP address your device connects from. PostHog uses that IP address to estimate a country and city when the events arrive, and is set to discard it instead of storing it with the events. The app does not ask for location permission and never reads your device's GPS.

Purchase events. When you start a trial, buy, renew, cancel or when a plan expires, RevenueCat sends a record of that event (for example the product, its price, RevenueCat's app user ID and Apple's transaction ID) to PostHog under the same random identifier, so we can see how the plans are used. See "Purchases and subscriptions" below.

What analytics never collects

We do not collect your name, email address, phone number, contacts, photos, files, precise location, calculations, inputs, answers, history or anything you type. We do not record your screen, and we do not collect crash reports.

Purchases and subscriptions (Apple and RevenueCat)

The app is paid: it offers a yearly subscription with a free trial for eligible new subscribers, and a one-time Lifetime purchase. Payments are made through Apple's App Store with your Apple Account. Apple processes the payment; KLM Labs never receives or stores your card or bank details.

RevenueCat, Inc. processes purchase records for KLM Labs so the app can check whether you have access, unlock it and restore it on another iPhone. RevenueCat receives your App Store purchase and subscription records (the product, Apple's transaction IDs, dates, trial and renewal status), a random app user ID that RevenueCat creates (there is no login), which set of plans the app showed you, technical details such as the app version, iOS version and App Store country, and the random PostHog identifier described above so purchase events can be matched with usage analytics. RevenueCat also receives your IP address when the app connects to it, and your iPhone's vendor ID (IDFV) when iOS provides one. iOS gives each app developer one vendor ID per iPhone, the same in all of that developer's apps; it is not the advertising identifier.

We use purchase records only to provide and restore your plan, to understand how the plans are used, and to handle your requests. We do not use them for advertising.

Reminders and notifications

If you start a free trial, the app can remind you 2 days before it ends. The reminder is a notification scheduled on your iPhone; it is not sent from a server, and no push token is sent to us. Before the plans screen, if you can get the free trial and haven't answered before, the app shows a page about the trial and asks for permission to send notifications. You can say no, or turn notifications off later in Settings; the app works the same either way.

The Stairs tool can make a one-page PDF of a stair layout. The PDF is created on your iPhone and opens the system share sheet. It leaves your device only if you choose a destination, which then handles it under its own privacy practices.

When you email us

If you email us for support or a privacy request, we receive your email address, your name if your email includes it, your message and any attachments you choose to send, such as screenshots. Google processes this mail for us through Gmail. We use it only to answer and handle your request.

Service providers

PostHog, RevenueCat and, for email, Google (Gmail) process data for KLM Labs. We require the service providers that receive personal data from us to protect it at the same or an equivalent level as this policy describes and Apple's App Review Guidelines require. We do not sell personal data or share it for advertising.

How long data is kept

On your device, History keeps the newest 1,000 calculations and removes older ones automatically. History → More (…) → Clear All removes the history and the widget's last answer; it does not clear the calculator's memory, saved tool inputs or settings. Deleting the app removes everything it stored on the device; copies in your backups, and anything you shared, are managed separately.

We keep analytics events, purchase records and support emails only as long as we need them to run, support and improve the app, or as the law requires (for example, purchase records for tax and accounting), and then delete them. Deleting the app does not delete records already sent to PostHog or RevenueCat; to ask us to delete them, see "Your choices and rights" below.

Children

Fraction Feet Inch Calculator is a tool for building and trade work and is not directed to children. We do not knowingly collect personal information from children. If you believe a child has used the app, contact us and we will delete any records we can find.

Your choices and rights

Delete your history with History → More (…) → Clear All, or delete the app to remove everything it stored. Device backups, if you have them on, are controlled by Apple and your settings, not by us.
Turn off reminders in your iPhone's Settings → Notifications.
Cancel a subscription in your Apple Account settings; see the terms of use. Deleting the app does not cancel it.
Ask us to delete analytics or purchase records. Email klm.labs.inc@gmail.com. Because these records use random identifiers rather than an account, tell us roughly when you used the app and, for purchases, when you bought, so we can find them. We will tell you what we could find and delete. Apple keeps its own purchase records.
Ask what we hold by emailing the same address.

Depending on where you live, you may have further rights over personal data, such as access, correction, deletion and objection. Contact us and we will respond as the law requires.

Changes to this policy

If the app's data practices change, we will update this policy and the App Store privacy details before that version is released. The effective date at the top shows the latest change. Questions: klm.labs.inc@gmail.com.