Privacy Policy

Last updated: 2026-10-26

This is the umbrella privacy policy for the TradeTools.dev family of mobile applications, developed and published by ZkDev — the developer name shown on our Google Play and App Store listings. Contact: support@tradetools.dev.

Each individual app has its own per-app privacy policy, listing that app by the exact name used on its store page and linked from the store listing — the principles below apply consistently across all apps.

What data we collect

Our apps collect minimal data for four purposes: (1) crash reporting, (2) anonymous usage analytics, (3) advertising on the free tier, and (4) verifying your Pro unlock. Specifically:

Crash reports via Firebase Crashlytics — anonymous device model, OS version, stack trace. No personal identifiers.
Anonymous usage analytics via Firebase Analytics — which screens, tools and features are used, plus coarse settings flags (trade, unit system, Pro status, whether a company profile exists, an estimate-count band). Tied to a random per-install ID, never to your name, email or account. Anonymous events about your own calculators and saved numbers — for example that one was opened, sent or imported, or that you saved your numbers — carry only a fixed label, never the calculator's name, its numbers, its prices or its costs.
Advertising via Google AdMob (free tier only) — IDFA / Advertising ID for personalized ads, subject to your iOS App Tracking Transparency (ATT) consent and Android consent.
Purchase history via Apple StoreKit / Google Play Billing — required to verify Pro unlock. Stored locally on your device, encrypted.

What we do NOT collect

Calculation inputs and results, and — for the TradeTools app — your company profile, clients, price list, documents, the calculators you build or import, and the numbers and prices you save in built-in tools (all stay 100% on your device, in encrypted local storage; the encryption key itself is kept in the device's own secure storage, e.g. Android Keystore or iOS Keychain)
Account information — our apps don't have user accounts
Email, phone number, name, or any contact information
Location data
We never upload photos or files; an image you pick as a logo, or a backup file you pick to restore, is read on your device only.

Pro purchases

Pro is a one-time purchase via the Apple App Store or Google Play — $2.99 for a single-purpose app, and a separate one-time price for TradeTools, which carries every calculator in one app. The transaction is between you and Apple/Google — we don't see your payment details. Pro status is verified locally on your device via the official StoreKit / Play Billing API.

TradeTools — Estimates and your own calculators

TradeTools stores your company profile (including a logo you upload), your clients' contact details, your price list, your estimates and your technical reports — on-device only, in the same encrypted local storage described above. This data leaves your device only in ways you start: an estimate or report you export as a PDF (saved to the app's temporary folder and, if you choose, shared); a backup file you choose to create and share to move your data to a new device; and a calculator you build or import, which you can send to your crew as a file or a code through the share sheet of your phone. Where it goes is the app you pick (for example your e-mail or messages app) — we have no server and receive nothing. A shared calculator carries its name, formulas, inputs and defaults, the numbers and prices you set in it, its example and your company name if you have one; it never carries your costs, clients or estimates. The backup file is plain, unencrypted text and contains readable client contact details, your calculators, your saved numbers and prices and your costs, so keep it safe. The other person's app reads a file or code you send on their device only; a calculator you receive is yours to check — TradeTools does not check it. A completed Pro purchase is reported to Firebase Analytics as an anonymous event — price, currency and the Pro product identifier only, no personal identifiers.

Children

Our apps are aimed at professional adults working in the trades. We do not knowingly collect data from children under 13.

Apps covered by this policy

All applications below are published by ZkDev on Google Play and the App Store. Each is listed by the exact name shown on its store page, together with its package identifier, so the policy can be matched to the listing it belongs to.