Privacy policy

Last updated: 9 September 2026. This policy describes the Android app Standard Deviation Calculator (package tq.tech.standarddeviation), published by TQ Tech.

Standard Deviation Calculator is a local-first statistics calculator. There is no account and no cloud sync of your datasets. Some components still use the internet: advertising (if you have not purchased Lifetime Pro), analytics, crash reports, and purchases.

Overview

This policy explains what data is stored on your device and which third-party services run when you use the app.

Data stored on your device

Everything you type stays on this device. Datasets, saved calculations (up to the 50 most recent), and your settings (theme, precision, and default calculation type) are stored locally with Android DataStore and Room. The calculator can compute results with no network connection. If Android backup is enabled, local app data can be included in device backup.

What we do not do

• No account creation or sign-in
• No cloud sync of datasets
• No selling of personal data

Advertising

If you have not purchased Lifetime Pro, advertising is served by the Google Mobile Ads SDK: one native ad after you calculate, an occasional interstitial after several calculations, an app-open ad when you return to the app, and an optional rewarded video that unlocks 8 decimal places for 30 minutes. Ads may use an advertising identifier. Lifetime Pro removes these ads.

Analytics and crash reports

Firebase Analytics and Crashlytics record anonymous usage events and crash reports so we can keep the calculator reliable. These services use the internet. They are not used to identify you personally. We do not ask you to type your name or email into analytics.

Purchases

Lifetime Pro is sold as a one-time in-app product through Google Play Billing. Purchase status is verified with RevenueCat so you can restore Lifetime Pro on this device. We do not receive your full payment card details — Google Play processes the charge.

Other Google Play services

Google Play’s review and update services are contacted only when you rate the app or when an update is available.

Children

The app is a general statistics calculator. We do not knowingly collect personal information from children for accounts, because there are no accounts.

Your choices

Uninstalling the app removes local data on that device (backups may persist until you delete them in Android). Lifetime Pro removes ads. You can restore a purchase from Settings or the paywall on the same Google Play account.

Contact

Questions about this policy: tqtechofficial@gmail.com. You can also use the developer contact listed on the Google Play listing for Standard Deviation Calculator when that listing is live.