Privacy should be understandable.

What stays on your device

Player names, settings, puzzle progress, rankings, daily-challenge history, session recovery, and difficulty feedback are stored locally. Numchemy does not require an account, and this local information is not sent to us by default.

Optional product analytics

A player’s optional data-sharing choice controls whether Numchemy uses Google Firebase Analytics to understand which games and features are useful. The limited event set covers game selection, puzzle start and finish, and opening features such as Daily Challenge, Ranking, Progress, Hint, Solution, My Work, Settings, and the rule guide.

Event details may include the game, ruleset, difficulty, play mode, outcome, source-number count, fixed or variable target type, move count, and active time rounded to seconds. Firebase may also process app and device metadata, installation or app-instance identifiers, and coarse location inferred from a masked IP address.

What we deliberately do not send

• Player or profile names, email addresses, or account identifiers
• The numbers, target, equation, or step-by-step calculation in a puzzle
• Precise location
• Free-form text or a detailed interaction trail

Optional diagnostics

With the same optional choice, Firebase Crashlytics may receive crash reports, stack traces, app state, device metadata, and installation or session identifiers. This helps us diagnose failures. Unsent reports are deleted when sharing is turned off.

Age choice

Numchemy can be used by adults and children. Each local player profile stores an age range on the device; the age range is not sent with analytics. An adult player can make their own sharing choice. For an under-18 player, sharing is off by default and can be enabled only after a parent or guardian makes the separate sharing choice. Numchemy does not ask for or store any parent or guardian details.

Optional rewarded ads

Numchemy may offer an optional Google AdMob rewarded ad for 30 extra seconds in Solo Sprint or eight additional Practice puzzles. Watching an ad is never required for the first Practice set, Daily Challenge, Face-to-Face, Progress, or ordinary play.

AdMob may process ad-request, app-interaction, device, diagnostic, and coarse network-location information to deliver, limit, secure, and measure an ad. Numchemy does not request Android's advertising-ID permission or Apple tracking permission. Under-18 and unknown-age players receive restricted, non-personalized requests with a General Audiences content ceiling. Ad choices are separate from optional Firebase analytics sharing.

Retention and control

Google Analytics event and user data retention is configured to two months. Firebase states that Crashlytics data is retained for 90 days. You can turn sharing off at any time in Numchemy Settings; this stops future optional collection, resets the app’s Analytics identifier, and deletes unsent crash reports. Previously received records remain subject to the retention periods above. Deleting the app removes its local data, subject to any backup or restore feature controlled by your device.

This website

This read-only website has no account, advertising, analytics, cookies, or contact form. Its hosting provider may process ordinary request data, such as an IP address and browser metadata, to deliver and secure the site.

Updates and questions

We will update this page when Numchemy’s data practices change. For privacy questions, email support@numchemy.com or visit the support page.