1Agreement to these terms
These Terms of Use (“Terms”) are a legal agreement between you and Zydeno, the developer of Windrung (“we”, “us”). They apply to the Windrung app for Android, its updates and everything it shows or produces (together, “the app”). By installing, opening or using the app you accept these Terms. If you do not accept them, do not use the app and uninstall it.
The Privacy Policy explains how the app handles data and forms part of these Terms. If we offer optional features under additional terms in the future, for example paid features, those terms will be shown to you before you accept them and will apply together with these Terms.
You must be old enough to enter into a binding contract where you live, or use the app with the consent and supervision of a parent or guardian who accepts these Terms for you. If you use the app for an organisation, you confirm that you may accept these Terms on its behalf; the consumer-protection provisions of these Terms apply only to consumers.
2Who provides Windrung
Windrung is developed and published by Zydeno (“we”, “us”), an independent developer. Contact: support@zydeno.com, website zydeno.com.
The app is intended for adults. If you are under the age of majority where you live, use it only with the involvement of a parent or guardian, and follow any minimum age that applies to operating drones in your country.
3What Windrung is and is not
Windrung is a weather-planning tool for drone pilots. It shows hourly forecasts of wind at several heights, gusts, precipitation, visibility, cloud base, temperature, light and twilight, a geomagnetic (Kp) outlook and estimated GNSS satellite visibility. It combines them with the limits of your drone profile into weather ratings: “Good flying weather”, “Marginal” and “Poor flying weather”.
Windrung does not check airspace, restricted areas, no-fly areas, notices to airmen, temporary restrictions, permits or the legal status of a flight. It does not know local regulations, your aircraft’s actual condition or the obstacles and people around you. The heights it shows (for example 10, 80, 120 or 180 m) are forecast levels, not legal altitude limits.
5Your responsibility as the pilot
You are responsible for every flight you make. In particular, you are responsible for:
- knowing and following the laws, airspace rules, registration, training, insurance and permit requirements that apply where you fly;
- checking actual conditions on site and stopping or not starting a flight when conditions differ from the forecast;
- setting drone-profile limits that match your aircraft. Built-in presets are conservative starting values, not manufacturer data: check your aircraft manual;
- the safety of people, animals and property, and respecting other people’s privacy, especially when surveying occupied buildings;
- night flying, which is subject to local rules (for example lighting and approval requirements). The app does not say that night flights are allowed.
6Forecasts, ratings and estimates
- Forecasts come from numerical weather models through Open-Meteo. The app interpolates them to your flight altitude and terrain. Wind near obstacles, terrain, coasts and thermals can differ greatly from any model.
- Model agreement compares three models to show how much they differ. Close agreement does not mean a forecast is right.
- Kp is a planetary index from NOAA SWPC. Local magnetic effects may differ.
- GNSS visibility is estimated on your phone from orbital data. Actual reception depends on terrain, obstacles and your receiver.
- Task presets (for example mapping or thermal surveys) contain weather and light reference values for planning, such as an irradiance value taken from IEC TS 62446-3. They do not certify results, do not make your work compliant with any standard and do not replace your own professional judgement.
- Notifications and the widget may be delayed or not delivered, for example because of battery optimisation, missing connectivity or the system, and may show cached data. Do not rely on them as the only source of information.
7Not professional advice; no safety-critical use
Check results before you rely on them
The forecasts, flight ratings, the Kp outlook and GNSS visibility estimates that Windrung shows are produced from models, published methods and data and the values you enter, and they can be wrong. Before relying on them for deciding whether, where and when to fly, check them against official aviation weather information and the rules of your aviation authority, and use your own judgement as the remote pilot in command.
The app is a tool to help you plan and calculate. It does not give professional, engineering, legal or other expert advice, and using it does not create a professional relationship with us. You remain responsible for your inputs, for how you interpret the results and for what you decide to do.
Do not use the app as the only basis for a decision where an error could cause death, personal injury, damage to property or the environment, or legal or financial loss, and do not use it in a safety-critical system, in an emergency or to control equipment. The app is not designed for crewed aviation and must not be used for it.
8Licence to use the app
Subject to these Terms, we grant you a limited, personal, revocable, non-exclusive, non-transferable and non-sublicensable licence to download, install and use the app on Android devices you own or control, for your own purposes. The app is licensed to you, not sold.
Except where these Terms, an open-source licence or mandatory law allow it (for example decompiling for interoperability where the law permits), you may not: copy, modify, translate or create derivative works of the app; decompile, disassemble or reverse-engineer it; rent, lend, sell, sublicense, distribute or publish it, or make it available for use by others over a network; remove or change any copyright, trademark or legal notice; or get around any technical limit of the app, including any future purchase, licence or advertising mechanism.
Open-source components and fonts in the app are licensed under their own licences, listed in the app under About → Open-source licenses. Those licences prevail for those components, and nothing in these Terms limits the rights they give you.
9Data sources and attribution
Windrung uses public data from the following independent providers. They do not endorse the app.
| Data | Source and licence |
|---|---|
| Weather forecasts | Weather data by Open-Meteo.com, licensed under CC BY 4.0. Values are interpolated to your flight altitude and combined into flight ratings by Windrung (modified). Underlying models include DWD, ECMWF, NOAA NCEP, Météo-France and others; see the Open-Meteo licence. |
| Model agreement | ECMWF IFS forecast data © European Centre for Medium-Range Weather Forecasts (ECMWF), licensed under CC BY 4.0; ICON by Deutscher Wetterdienst (DWD); GFS by NOAA NCEP. All accessed via Open-Meteo.com. |
| Place search | Open-Meteo Geocoding API. Location data based on GeoNames, CC BY 4.0. |
| Kp index forecast | NOAA Space Weather Prediction Center (swpc.noaa.gov). U.S. Government information, not subject to copyright in the U.S. Windrung is not affiliated with or endorsed by NOAA. |
| GNSS orbital elements | CelesTrak, derived from USSPACECOM data via Space-Track.org. Satellite visibility is computed on your device with the SGP4 orbit model. |
| Typeface | Geologica, © The Geologisk Project Authors, SIL Open Font License 1.1. |
The same attributions appear in the app under About → Data sources. Each provider’s data remains subject to its own terms.
10Third-party services
The app depends on services we do not operate. They may change their data, limit the number of requests, or become unavailable at any time, and the app may then show older cached data or no data. We are not responsible for the content, availability or policies of these services, or of websites the app links to. Links open in your browser.
11Acceptable use
You agree not to:
- use the app in breach of any law or of other people’s rights;
- use the app to send automated or bulk requests to the data providers, or otherwise work around their usage limits;
- remove or hide attributions and legal notices, or present the app’s output as an official briefing or authorization;
- copy, modify, redistribute, sell or reverse-engineer the app, except as allowed by law or by an open-source licence.
You also agree not to:
- use the app, or data obtained through it, in a way that is unlawful, fraudulent or harmful, or that infringes anyone’s intellectual property, privacy or other rights;
- enter, store or pass on other people’s personal data with the app unless you are allowed to do so;
- interfere with or disrupt the app or any service it connects to, introduce malicious code, or try to gain unauthorised access to any system;
- use automated means to extract data from the app or from the services it uses beyond normal personal use;
- present the app or its output as official, certified or endorsed by any authority, manufacturer or data provider.
12Your data and backups
Your places, drone profiles, plans and settings are stored only on your device. You own them. We do not have a copy and cannot recover them if you lose your phone, uninstall the app or use “Delete all data”. Use Export in Settings to keep your own backup. See the Privacy Policy for details.
13Intellectual property
The app, its design, text, icon and the name Windrung belong to the developer, except for third-party data and open-source components, which belong to their owners. FAA, EASA, NOAA, Open-Meteo, CelesTrak and other names are used only to describe sources and rules. They belong to their respective owners. Windrung is an independent app and is not affiliated with any government agency, aviation authority or drone manufacturer.
The names Zydeno and Windrung and their logos are our marks. You may refer to them to describe the app accurately, but not use them in a way that suggests endorsement. Names of third parties appear only to identify data sources, file formats, standards or rules; they belong to their owners and do not imply endorsement. If you send us feedback or ideas, we may use them without any obligation to you. We claim no rights in your own projects, data or exported files.
14Price, payments, ads and future paid features
Current version. The current version of Windrung is provided free of charge, without ads and without in-app purchases or subscriptions. This describes the current version only. It is not a promise that the app, or any feature of it, will remain free of charge or free of ads.
Possible changes. We may at any time introduce advertising; offer paid features, in-app purchases, subscriptions or a paid edition; change which features are free; and set or change prices. Features that are free today may require payment in a future version. We will describe such changes in the store listing and release notes, and in the Privacy Policy where they affect data.
Purchases. Any purchase will be made through Google Play and processed by Google under the Google Play Terms of Service and its payment policies. Prices are shown in Google Play before you buy, including taxes where applicable. Subscriptions renew automatically until you cancel them in Google Play; cancelling stops future renewals. Refunds follow Google Play’s refund policies and your mandatory consumer rights, such as the right of withdrawal in the EU and the UK. Where you ask for immediate access to digital content during a withdrawal period, you may lose that right to the extent the law allows, and you will be asked to confirm this before you buy. You are charged only if you choose to buy something.
Ads. If the app shows ads, they are supplied by third parties. We are not responsible for the content of ads or for the products and services advertised, and any dealings with advertisers are between you and them.
Price changes. We may change prices for future purchases at any time. For an active subscription, we will announce a price increase as Google Play and the law require, and you can cancel before it applies.
15Disclaimer of warranties
To the maximum extent permitted by law, the app and all data in it are provided “as is” and “as available”, without warranties of any kind, express or implied, including warranties of accuracy, timeliness, reliability, fitness for a particular purpose, merchantability and non-infringement. We do not warrant that forecasts or ratings are correct, that the app is free of errors or that it will be available without interruption.
In particular, and to the maximum extent permitted by law, we do not warrant that the app will meet your requirements, run without interruption, be compatible with your device or be free of errors or harmful components; that defects will be corrected; that data from third-party sources is accurate, complete or current; or that any feature, data source or price will remain available or unchanged.
Nothing in these Terms excludes or limits warranties, guarantees or conformity rights that cannot be excluded under the law that applies to you as a consumer (§17).
16Limitation of liability
To the maximum extent permitted by law, the developer is not liable for any indirect, incidental, special, consequential or punitive damages, or for loss or damage to aircraft, equipment or other property, loss of data, fines, lost profits or business losses, arising from or related to the app, its data or decisions based on them, even if we were told such damage was possible.
Cap. To the maximum extent permitted by law, our total liability for all claims arising out of or relating to the app or these Terms is limited to the greater of (a) the total amount you paid us for the app and in-app purchases in the 12 months before the event giving rise to the claim and (b) 50 euros or the equivalent in your local currency. For the current version, which is free of charge, you have paid nothing.
These limits apply whatever the legal basis of the claim (contract, tort including negligence, strict liability or otherwise), even if a limited remedy fails of its essential purpose. They are part of the basis on which we make the app available.
What we do not limit. Nothing in these Terms excludes or limits liability for death or personal injury caused by our negligence; for fraud or fraudulent misrepresentation; for damage caused intentionally or by gross negligence; under mandatory product-liability law (including, where it applies, Directive (EU) 2024/2853 on liability for defective products and the UK Consumer Protection Act 1987); or any other liability that cannot be excluded or limited by law. Where the law allows only a partial limitation, our liability is limited to the extent it permits.
17Your rights as a consumer
If you use the app as a consumer, you benefit from the mandatory consumer-protection rules of the country where you live, and nothing in these Terms affects them. In particular:
- EU and EEA: your statutory rights, including those on the conformity of digital content and digital services under the national rules implementing Directive (EU) 2019/770 where they apply, and mandatory product-liability rules, remain unaffected.
- United Kingdom: your statutory rights, including under the Consumer Rights Act 2015, remain unaffected.
- Australia: our services come with guarantees that cannot be excluded under the Australian Consumer Law. Where the law allows us to limit our liability for failing to meet a consumer guarantee for services that are not of a kind ordinarily acquired for personal, domestic or household use, our liability is limited to supplying the services again or paying the cost of having them supplied again.
- New Zealand: if you acquire the app for business purposes, you agree that the Consumer Guarantees Act 1993 does not apply, to the extent the law permits.
- United States and Canada: some states and provinces do not allow the exclusion of implied warranties or the limitation of incidental or consequential damages, so some of the exclusions above may not apply to you. In Québec, the mandatory provisions of the Consumer Protection Act apply.
18Indemnity
To the extent permitted by law, you agree to indemnify and hold harmless the developer against claims, liabilities, damages, losses and reasonable costs, including reasonable legal fees, brought by third parties and arising out of (a) your flights and drone operations, (b) your breach of these Terms, (c) your violation of any law or of the rights of others, or (d) output of the app that you provide to another person, such as a client or employer. This does not apply to the extent a claim is caused by our own breach of these Terms or our negligence, or where local consumer law does not allow it.
19Changes, availability and termination
To the extent the law allows, we may change, update, add or remove features, change data sources, and suspend or discontinue the app, in whole or in part or in any country, at any time. Data sources may change or end, and parts of the app may then stop working or show older cached data. We are not obliged to provide updates, maintenance or support, except where mandatory consumer law requires updates to keep the app in conformity.
You may stop using the app at any time by uninstalling it. Your licence ends automatically if you materially breach these Terms, and we may end or suspend it where the law requires. When it ends, you must stop using the app and uninstall it. Your data stays on your device under your control, so export what you need first.
Provisions that by their nature should continue after these Terms end continue to apply, including those on intellectual property, disclaimers, limitation of liability, indemnity, governing law and general provisions.
20Google Play
You obtain the app through Google Play. Your download, and any purchase you make, is also governed by the Google Play Terms of Service and Google’s policies. Where these Terms conflict with Google Play’s terms on the distribution, billing, refunds or licensing of apps obtained from Google Play, Google Play’s terms prevail to the extent of that conflict.
These Terms are between you and the developer only, not Google. Google is not responsible for the app or its content and has no obligation to provide maintenance or support for it. Android and Google Play are trademarks of Google LLC.
21Governing law and disputes
These Terms, and any dispute or claim arising out of or in connection with them or the app, including non-contractual disputes, are governed by the law of the country in which the developer is established, without regard to its conflict-of-laws rules. The United Nations Convention on Contracts for the International Sale of Goods does not apply.
The courts competent for the place where the developer is established have jurisdiction. If you are a consumer, you keep the protection of the mandatory provisions of the law of your country of residence, and you may bring proceedings in the courts of that country where that law allows it.
Before starting formal proceedings, please write to support@zydeno.com and give us at least 30 days to try to resolve the issue informally. This does not affect any time limit that applies to you by law or your right to use an alternative dispute-resolution body available to consumers in your country.
22General provisions
- Entire agreement. These Terms, the Privacy Policy and any additional terms you accept for optional features are the entire agreement between you and us about the app.
- Severability. If a provision is found invalid or unenforceable, it applies to the maximum extent permitted and the rest remains in effect.
- No waiver. Not enforcing a provision is not a waiver of the right to enforce it later.
- Assignment. You may not transfer your rights or obligations under these Terms. We may transfer ours, for example together with the app to another developer; where the law requires, this will not reduce your rights as a consumer.
- Events beyond our control. We are not responsible for failure or delay caused by events beyond our reasonable control, such as outages of networks, devices or third-party services, natural disasters or acts of authorities.
- Export and sanctions. You agree to use the app in compliance with applicable export-control and sanctions laws.
- No third-party rights. No one other than you and us may enforce these Terms.
- Notices. We may give notices in the app, in its store listing or release notes, or on this page. You can send notices to support@zydeno.com.
- Language. These Terms are written in English, which is the binding version. A translation, if offered, is for convenience only, unless the law of your country requires otherwise.
23Changes to these terms
We may update these Terms, for example when we change the app, introduce ads or paid features (§14), or when the law changes. The effective date and version at the top of this page show which version applies, and the version history (§24) summarises the changes.
For material changes we give reasonable notice before they take effect, for example in the release notes or in the app. If you keep using the app after the changes take effect, you accept the updated Terms; if you do not agree, stop using the app and uninstall it. Changes do not apply to disputes that arose before they took effect.
24Version history
| Version | Effective | Changes |
|---|---|---|
| 2.0 | 2026-10-18 | Rewritten and expanded: licence, professional-use disclaimer, price and possible future ads or paid features, consumer rights by region, indemnity, Google Play, governing law, version history. |
| 1.0 | 2026-10-15 | First published. |
25Contact
- Developer: Zydeno, the developer of Windrung on Google Play
- E-mail: support@zydeno.com
- Website: zydeno.com
See also the Privacy Policy.