Privacy Policy — Metrical

Metrical (listed as „Metrical – Easy Unit Converter" in the App Store) is an app for converting units and currencies on iPhone, iPad and Mac. Privacy here is refreshingly simple: the app collects no personal data, shows no ads, and includes no analytics, tracking or crash-reporting services. There is no user account and no sign-in.

Controller

The party responsible for any data processing in connection with this app is:
Andreas Maier
Dürerstraße 14
73547 Lorch
Germany
Email: support@amapps.app

What data does the app process?

The app processes no personal data and transmits none to us or to third parties. It requests no sensitive permissions (no access to location, contacts, camera, microphone, etc.). The only permission it needs is internet access, used for the optional download of current exchange rates (see below).

Local storage on your device

Stored only locally on your device, in the app's own storage:

• the category and unit you last chose, so the app opens where you left it,
• the exchange rates last downloaded, together with their date, so currencies keep working without an internet connection,
• whether the full version was purchased and whether the intro screen has been shown,
• how often the app has been opened — from which it decides when it may politely ask for a review.

This information never leaves your device, is not transmitted to any server, and is removed again when you uninstall the app.

Downloading exchange rates (currency conversion)

For currency conversion, the app downloads daily exchange rates directly from the European Central Bank (ECB) (ecb.europa.eu). As with any request to an internet address, this necessarily transmits your device's IP address to the ECB server. No further data is sent, no identifiers are set and no profiles are built. The ECB server is located in the European Union.

If the ECB cannot be reached — on older system versions the connection fails on a security certificate not yet known there — the app falls back to a secondary source at amapps.app/rates/, which holds an unmodified copy of the same ECB file. That address is ours, but is technically served by GitHub Pages (GitHub, Inc., USA); this transmits your IP address to GitHub, and their own privacy terms apply in addition. We keep no logs of these requests and learn nothing about them. Here too, no further data is sent and no identifiers are set.

The legal basis for both requests is Art. 6(1)(f) GDPR (legitimate interest in providing current rates).

All other (physical) conversions work entirely offline, with no internet connection at all.

No ads, no tracking

The app contains no ad networks, no analytics or crash-reporting SDKs and no cross-device tracking. No advertising or device IDs are read.

In-app purchases

The app is free and converts in full. In-app purchases are offered optionally (a monthly or yearly subscription, and a one-time purchase) which unlock the full version and permanently remove the hint screen shown occasionally. Purchase, billing and management run exclusively through the App Store; we receive no payment or personal data in the process, and no account with us is required. The App Store's terms of use and subscription terms apply in addition.

Review prompt

After a number of launches, the app asks once whether you would like to rate it in the App Store. That dialog comes from Apple itself (SKStoreReviewController); the app learns neither whether you answered it nor how. No data is transmitted to us.

Obtaining the app via the App Store

The app is downloaded through the Apple App Store. Apple's own privacy terms govern any data processing they carry out in that context; we have no influence over it.

Your rights

Under the GDPR you have the rights of access (Art. 15), rectification (Art. 16), erasure (Art. 17), restriction of processing (Art. 18), data portability (Art. 20) and the right to object (Art. 21). Since the app stores no personal data with us, we generally hold no data to which these rights could apply. You can remove the information stored locally on your device at any time by clearing the app's data or uninstalling it. For any concerns, you can reach us at the contact details above.

Right to lodge a complaint

You have the right to lodge a complaint with a data protection supervisory authority. The authority responsible at our place of business is:
Der Landesbeauftragte für den Datenschutz und die Informationsfreiheit Baden-Württemberg (LfDI BW), Lautenschlagerstraße 20, 70173 Stuttgart, Germany.

Last updated

This privacy policy was last updated in September 2026. It will be adjusted whenever the app changes.