1Who we are
Windrung (“the app”) is a weather-planning app for drone pilots on Android. It is developed and published by Zydeno (“we”, “us”, “the developer”), an independent developer. For anything related to privacy, write to support@zydeno.com. More about us: zydeno.com.
Developer identity. Zydeno is the developer name under which Windrung is published on Google Play, as shown on the app’s store listing. For the purposes of data-protection law, the developer is responsible (the “controller”) for the limited personal data described in this policy that actually reaches us, such as e-mails you send us. Data that stays on your device is under your control. Data that the app sends directly from your phone to the independent services listed in §5 is received and handled by those services under their own policies; we never receive it.
2Scope of this policy
This policy covers the Windrung Android app distributed through Google Play, including its home-screen widget and its optional daily notification. It explains what stays on your device, what the app sends over the internet and to whom.
It does not cover the independent services the app contacts for public data (Open-Meteo, NOAA SWPC, CelesTrak; see §5), or Google Play and Android themselves. Those are governed by their own policies, for Google see the Google Privacy Policy. Our Terms of Use describe the rules for using the app.
3What the developer does not collect
Windrung has no backend of ours. The developer does not receive or store any personal data about you. In particular, the app:
- has no account, sign-in, e-mail or phone-number field;
- does not send anything to a Zydeno server (the privacy and terms pages open in your browser, the app itself does not contact zydeno.com);
- contains no advertising, analytics, attribution or crash-reporting SDKs. The app has no ads and no analytics;
- does not use the Android advertising ID (the permission is removed from the app) and does not create any device or user identifier;
- does not track you across other apps or websites;
- does not sell, rent or share personal information with data brokers or advertisers.
4Data stored on your device
Everything you create in Windrung lives in the app’s private storage on your phone:
- Places: name, region, the coordinates you chose or that came from your approximate location, take-off elevation and time zone;
- Drone profiles: aircraft class, wind and temperature limits, flight altitude, the GNSS and darkness rules you set;
- Shoot plans and the pre-flight checklist;
- Settings: units, app language, theme, the daily notification time and places, widget options;
- Cached public data: recent forecasts, model comparison, the Kp forecast and GNSS orbital elements, so the app works offline and does not repeat requests.
The full-precision coordinates of your places stay on the device. Sunrise, twilight, satellite visibility and flight ratings are computed on the phone. Recent place-search results are kept only in memory while the app runs.
Windrung opts out of Android cloud backup and device-to-device transfer, so its data is not copied to your Google account. To move your data to another phone, use Export and Import (§11).
5Data that leaves your device
The app makes only the requests listed below, all over encrypted HTTPS (unencrypted traffic is disabled). It attaches no name, account, advertising ID or other identifier and sets no cookies.
| When | What is sent | To whom | Why |
|---|---|---|---|
| You open or refresh a place, compare places, or the daily notification runs (up to 3 places you picked) | The place’s coordinates rounded to 0.02° (about 2 km), the list of weather variables and the forecast length | Open-Meteo forecast API (api.open-meteo.com) |
To get the hourly forecast, including the comparison of three weather models for the place you are viewing |
| You type a place name in search (after a short pause, from 3 characters, or 2 for Chinese, Japanese and Korean) | The search text and the app’s language code | Open-Meteo geocoding API (geocoding-api.open-meteo.com) |
To find matching places and their coordinates |
| The app updates the geomagnetic outlook (at most every 3 hours) | Nothing about you: a download of a public file | NOAA Space Weather Prediction Center (services.swpc.noaa.gov) |
To show the Kp index forecast |
| You open satellite information (at most every 12 hours) | Nothing about you: a download of a public file | CelesTrak (celestrak.org) |
To compute GNSS satellite visibility on your phone |
Like any internet connection, each request reveals your device’s IP address to the server it reaches. Each request also carries a technical header that names the app and its version and our support address (Windrung/1.0.0 (support@zydeno.com)). It identifies the app, not you.
What Open-Meteo keeps
According to the Open-Meteo terms, Open-Meteo may collect IP addresses for technical reasons, keeps web-server logs that may contain geographical coordinates, deletes those logs after 90 days and does not share them with third parties. Your rounded coordinates and search text can therefore remain in Open-Meteo’s logs for up to 90 days. We (the developer) do not receive or store them.
NOAA SWPC is part of the U.S. National Weather Service, see the NWS privacy policy. CelesTrak publishes its policies on celestrak.org. We do not control how these services handle requests.
In Google Play’s Data safety section these flows are declared as Approximate location and In-app search history: collected for app functionality only, not shared, encrypted in transit and optional. They are declared as collected because the data leaves your device, even though it goes directly to Open-Meteo and never to us.
6Location
- Optional. Windrung works fully without location access: you can search for a place or enter coordinates.
- Approximate only. The app requests only Android’s approximate location permission (
ACCESS_COARSE_LOCATION). It does not request precise location or background location. - On request. The permission is requested only after you tap “Use approximate location” and read a short explanation. The app then reads your approximate position once to add or move the place “My approximate location”.
- Rounded before it leaves. Before any forecast request, coordinates (whether from your location or typed by you) are rounded to 0.02°.
- No background location. The daily notification uses the saved coordinates of your places and does not read your location.
You can withdraw the permission at any time in Android Settings → Apps → Windrung → Permissions.
7Notifications and background work
The daily notification about flying windows is off until you switch it on. On Android 13 and later, the app asks for the notification permission at that moment. The notification is scheduled on the device with Android WorkManager, about once a day, with no exact alarms and no push server.
When it runs, the background task refreshes forecasts for up to three places you chose, sending rounded coordinates to Open-Meteo as described in §5. The text of the notification is computed on your phone and never leaves it. Turning the notification off cancels the task.
8Home-screen widget
The widget shows the current rating and flying windows from data the app has already stored. It makes no network requests of its own. If you prefer not to show a place name on your home screen, you can switch on “Hide place name on the widget” in Settings.
9Other on-device features
- Sunlight mode. The app can read the phone’s ambient light sensor to switch to a high-contrast theme in bright sun. The readings are used on the spot and are not stored or sent.
- Share. When you tap Share, the app passes a short text summary to the Android share sheet. You choose the app and the recipient. Nothing is shared without that action.
- Demo mode. The demo uses recorded sample data bundled with the app and sends nothing.
- Language. The app language you choose is stored by Android’s per-app language setting on your device.
10Android permissions
| Permission | Why Windrung uses it | What leaves the device |
|---|---|---|
| Internet, network state | To download forecasts, place search results, the Kp forecast and satellite data, and to wait for a connection before a background refresh | Only the requests in §5 |
| Approximate location (optional) | To add a place at your current approximate position | Rounded coordinates to Open-Meteo, only when a forecast is requested |
| Notifications (optional) | To show the daily flying-windows notification you switched on | Nothing |
| Run at startup, prevent sleep | Used by Android WorkManager to keep the daily schedule after a restart and finish a short background refresh | Nothing |
The app also declares an internal, signature-protected permission that AndroidX libraries use to keep their broadcasts private to the app. It grants no access to your data.
11Export, import and deletion
- Export data saves your places, profiles, plans, checklist and settings to a JSON file at a location you pick with the Android file picker. The file goes only where you put it.
- Import restores such a file and replaces the current data (with an undo).
- Delete all data (in Settings and in About) erases everything the app has stored and stops the daily notification. The app offers to export a copy first.
- You can also delete individual places, profiles and plans, clear the cache, or uninstall the app, which removes all of its data.
12Legal bases for processing
Where the EU or UK GDPR, or a similar law such as the Swiss FADP or Brazil’s LGPD, applies, these are the legal bases for the limited processing described in this policy:
| Processing | Where it happens | Legal basis |
|---|---|---|
| Storing your entries and settings in the app’s private storage | Your device only; we never receive it | Necessary to provide the app you choose to use (Art. 6(1)(b) GDPR). Storage on your device is strictly necessary for that service, so no separate consent is needed under the ePrivacy rules. |
| Reading your device location when you ask the app to | Your device and, rounded, in the requests described in §5 | Your consent, which you give and can withdraw at any time through Android’s location permission (Art. 6(1)(a) GDPR). Withdrawing it does not affect earlier use. |
| Showing notifications you switch on | Your device only | Necessary to provide the feature you enabled (Art. 6(1)(b) GDPR). You can switch it off in the app or in Android settings. |
| Requests the app sends to fetch weather forecasts, place search, the Kp outlook and satellite data | The independent services in §5, under their own policies | Necessary to provide the function you request (Art. 6(1)(b) GDPR) and our legitimate interest in offering it with as little data as possible (Art. 6(1)(f) GDPR). |
| E-mails you send to support@zydeno.com | The developer and its e-mail provider | Our legitimate interest in answering you and improving the app (Art. 6(1)(f) GDPR) or steps you ask us to take (Art. 6(1)(b)); keeping records where the law requires it (Art. 6(1)(c)). |
The app makes no automated decisions that have legal or similarly significant effects on you, does not build a profile of you and does not process special categories of personal data.
13Retention
We keep nothing, because we receive nothing. Data on your device stays until you delete it or uninstall the app. Cached forecasts are replaced as new data arrives. Open-Meteo deletes its server logs after 90 days, according to its terms. Exported files are kept wherever you saved them, under your control.
Support e-mails. We keep e-mails you send us, and our replies, only as long as needed to handle your request and any follow-up, normally no longer than 24 months after the last message, unless the law requires us to keep them longer or we need them to establish, exercise or defend legal claims. You can ask us to delete them earlier.
14Your privacy rights
Privacy laws in many countries give you rights over your personal data. Because Windrung keeps your data on your phone and the developer does not receive it, most of these rights are in your own hands: you can view, correct, export and delete everything in the app (§11) and withdraw permissions in Android Settings. For data you have sent us, such as e-mails, write to support@zydeno.com.
Data that the app sends directly to the services in §5 is held by those services, not by us. We cannot see or delete it. To exercise your rights over it, contact them using the links in §5; we will help where we reasonably can.
EU and UK representative. The individual developer does not process personal data of people in the EU/EEA or the UK except occasional e-mails you choose to send to support. This occasional processing does not involve large-scale processing of special-category or criminal-offence data and is unlikely to result in a risk to your rights and freedoms. Under Article 27(2)(a) GDPR and Article 27(2)(a) UK GDPR, it does not require an EU or UK representative, so none is appointed. Contact us directly at support@zydeno.com; you can also complain to your local supervisory authority.
Rights by region. A summary; the law where you live decides the details.
- European Union, EEA, United Kingdom and Switzerland (GDPR, UK GDPR, Swiss FADP): access, rectification, erasure, restriction of processing, data portability, objection to processing based on legitimate interests, withdrawal of consent at any time, and complaint to a supervisory authority, for example in the country where you live or work (in the UK, the Information Commissioner’s Office).
- United States (California CCPA as amended by the CPRA, and the comprehensive privacy laws of other states such as Virginia, Colorado, Connecticut, Texas and Oregon): to know and access, delete, correct and port personal information; to opt out of its sale or sharing, of targeted advertising and of profiling; to limit the use of sensitive personal information; to appeal a refusal; to use an authorised agent; and not to be discriminated against for using these rights. Notice for California residents: in the last 12 months the developer has not collected personal information through the app, other than e-mails you chose to send us. Data the app sends directly from your device to the independent services described in §5 does not reach us. We have not sold or shared personal information, and we do not use sensitive personal information. Global Privacy Control signals are honoured where the law requires; today there is nothing to opt out of.
- Canada (PIPEDA and provincial laws, including Québec’s Law 25): access, correction and withdrawal of consent; complaints to the Office of the Privacy Commissioner of Canada or, in Québec, the Commission d’accès à l’information.
- Brazil (LGPD): confirmation of processing, access, correction, anonymisation, blocking or deletion, portability, information about sharing and revocation of consent; complaints to the ANPD.
- Japan (APPI): disclosure, correction, suspension of use or deletion; complaints to the Personal Information Protection Commission.
- South Korea (PIPA): access, correction, deletion, suspension of processing and withdrawal of consent; complaints to the Personal Information Protection Commission or the KISA privacy centre. The person responsible for personal information is the developer, reachable at support@zydeno.com.
- Australia and New Zealand (Privacy Act 1988, Privacy Act 2020): access and correction; complaints to the OAIC or the New Zealand Privacy Commissioner.
- Other countries (for example India’s DPDP Act, Singapore’s PDPA, South Africa’s POPIA or Türkiye’s KVKK): the rights your local law gives you. Write to us and we will respond in line with it.
How we respond. We answer within one month, or sooner or later where your local law sets another period (for example 45 days under the CCPA), and we may extend it where the law allows. We may ask for information to confirm that a request comes from you. Requests are free unless they are manifestly unfounded or excessive. If we cannot do what you ask, we explain why and how you can appeal or complain.
15International users
Windrung is available in many countries. The developer does not receive the data you keep in the app, so we do not transfer it anywhere. Requests the app makes go directly from your phone to the services in §5, which may process them on servers in other countries, including the European Union and the United States; their policies describe how they protect it.
If you e-mail us, your message is processed by our e-mail provider and may be stored on servers outside your country. Where the GDPR or UK GDPR applies to such a transfer, it relies on an adequacy decision, on standard contractual clauses offered by the provider, or on the transfer being necessary to answer your request.
This policy is written in English. If a translation is offered, the English version prevails unless your local law requires otherwise.
16Security
All network requests use HTTPS, and unencrypted connections are disabled in the app. Your data is protected by Android’s app sandbox and device encryption, and is excluded from cloud backups. Keep exported files somewhere safe, because they contain your places and plans. No method of storage or transmission is completely secure, so our main safeguard is sending as little as possible.
17Ads, purchases and future versions
Today. The current version of Windrung is free of charge, shows no ads, has no in-app purchases or subscriptions, and contains no advertising, analytics or payment SDKs. This describes the app as it is now, not a promise about future versions. Future versions may introduce advertising, paid features, in-app purchases or subscriptions, or other optional services.
If ads are introduced. Ads would be supplied by a third-party ad network, for example Google AdMob. Ad networks typically process your device’s advertising ID, IP address, approximate location derived from the IP address, device and app information and your interactions with ads, in order to show ads, limit repetition, measure performance and prevent fraud, and, only where you allow it, to personalise ads.
If purchases or subscriptions are introduced. They would be processed by Google Play’s billing system. Google handles your payment details under the Google Privacy Policy. We would receive only what is needed to deliver and verify a purchase, such as a purchase token, the product, its status, the country and the currency, never your full card or bank details.
Before any such change we will update this policy with a new effective date and version, describing what data is processed, by whom, why and how you can control it; update the Google Play Data safety section; mention the change in the release notes; ask for your consent where the law requires it (for example for personalised ads and non-essential access to your device in the EEA, the UK and Switzerland, through a consent tool that meets Google’s requirements); and offer the opt-outs the law requires (for example under US state privacy laws). The change applies only from the app version that introduces it. Data already stored in the app will not be used for advertising without telling you first and, where required, getting your consent. We will not knowingly show personalised ads to children (§18).
18Children
Windrung is a planning tool for drone pilots and is not directed to children. It does not knowingly collect personal information from anyone, including children under 13 (or the minimum age in your country). Many countries also set a minimum age for operating drones. Please follow those rules.
Age limits. In the EEA and the UK we also treat as a child anyone under the age at which a child may consent to online services in their country (between 13 and 16). If you are a parent or guardian and believe that your child has sent us personal data, for example by e-mail, write to support@zydeno.com and we will delete it. If a future version includes advertising, it will be set up in line with applicable children’s privacy rules, such as COPPA in the United States, and Google Play’s policies.
19Changes to this policy
We may update this policy when we change the app (including any change described in §17), when the services the app uses change, or when the law changes. The effective date and version at the top of this page show which version applies, and the version history (§20) summarises every change.
For a material change, for example new data leaving your device, ads or purchases, we update this page and the Google Play Data safety section before the app version with that change is published, describe it in the release notes, and ask for your consent in the app where the law requires it. Changes do not apply retroactively to data processed before them. Earlier versions are available on request from support@zydeno.com.
20Version history
| Version | Effective | Changes |
|---|---|---|
| 3.0 | 2026-10-20 | Clarified the individual developer's occasional support e-mail processing and the EU and UK representative exemption under Article 27(2)(a) GDPR and UK GDPR. No change to how the app handles data. |
| 2.0 | 2026-10-18 | Rewritten and expanded: developer identity, legal bases, rights by region, international users, possible future ads and paid features, version history. No change to how the app handles data. |
| 1.0 | 2026-10-15 | First published. |
21Contact
- Developer (controller): Zydeno, the developer of Windrung on Google Play
- E-mail for privacy questions and requests: support@zydeno.com
- Website: zydeno.com
We aim to answer within 30 days. If you are not satisfied with our answer, you can contact your local data-protection authority.
See also the Terms of Use.