1Who we are
Umbraday (“the app”) is an offline guide and chronometer for the total solar eclipse of 2 August 2027 and other eclipses included in the app, for Android. You choose a place, and the app calculates the eclipse times for it on your phone. 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 Umbraday 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.
2Scope of this policy
This policy covers the Umbraday Android app distributed through Google Play. It explains what the app stores, what it can hand over and when. It does not cover Google Play and Android themselves, or the apps and services you choose to use together with Umbraday (a maps app, a print service, a text-to-speech engine, your browser or e-mail app). 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, including the eye-safety rules.
3What the developer does not collect
Umbraday has no backend of ours and no internet access at all (see §7). 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;
- never connects 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 read your contacts, photos, files, camera or microphone. It has no camera or recording feature;
- does not sell, rent or share personal information with anyone.
4Your location
Umbraday works fully without location access: you can search the built-in list of places, type or paste coordinates, or drop a pin on the map. Location is used only as an optional shortcut.
- When: only after you tap “Use my location”. The app first explains why it needs location, and only then shows Android’s own permission dialog. It never asks in the background and does not request background location.
- Which permission: approximate location is enough for times to within minutes; precise location lets the app place you more exactly and is used for the optional clock check below. You can allow either or refuse; the app keeps working.
- How: the app asks Android (the system
LocationManager) for a single position and stops listening as soon as it has one or after a timeout. It does not use Google Play services location and keeps no location history. - What for: to calculate the eclipse contact times, the Sun’s height and the map position for where you are.
- Where it goes: nowhere. The position is processed only on your phone. The app has no internet permission and no code that sends coordinates to us or to anyone else.
- What is stored: the position is saved on your phone as a place (called “My location” in the app) with its coordinates, height if available, time zone and accuracy, plus the time and accuracy of the last fix. You can delete the place at any time.
Clock check. If you allow precise location and tap the clock check (in Preflight or on the chronometer), the app listens for a few GPS fixes and compares your phone’s clock with the time signal from the satellites. The result (the offset in seconds, whether it was confirmed, and when) is stored on your phone and used to warn you if your clock is off. The app never changes your clock, and applies a correction to its own times only if you tap the button for it.
What Android itself may do
On many phones the system’s location services use mobile-network and Wi-Fi information, and may contact Google or your phone maker’s location service, to work out a position. That is done by Android under your device’s location settings, not by Umbraday, and it is governed by their policies. Umbraday only receives the resulting coordinates. If you prefer to avoid this, do not use the button; search for a place, type coordinates or use the map instead.
5Data on your device
Everything you create in Umbraday lives in the app’s private storage on your phone:
- Places: the places you saved or selected (by search, typed coordinates, map pin or location), with the name, coordinates, height and time zone, and the places you compare;
- Cue journal: after a rehearsal or on eclipse day, a log of which cues played and when, against the plan, with the place name, and your marks (for example “observed”);
- Checklist and photo plan: the checklist items you tick and the camera settings (ISO, aperture, focal length, number of frames) you enter for the photo planner;
- Settings: language, theme, units, haptics, which cues are on, reminder choices, whether you have finished onboarding and read the eye-safety card, and similar preferences;
- Clock check result: described in §4;
- Spoken cues: short audio files of the app’s fixed phrases, produced in advance by your phone’s text-to-speech engine (see §7). They contain no personal data, can be recreated at any time and are not part of backups.
Names you type are your own data
Coordinates and eclipse times are not secret, but a place name such as the name of a hotel or a house is yours. It is stored like everything else, only on your phone, and it can appear in the cue journal, in a backup file you export and on a contact card you print.
Umbraday opts out of Android cloud backup and device-to-device transfer, so its data is not copied to your Google account or to a new phone automatically. To move your data to another phone, use the backup export and import described in §9.
6Permissions the app asks for
| Permission | Why | When |
|---|---|---|
| Location (approximate and precise) | Place yourself for the calculations; optional clock check against GPS time | Only after you tap “Use my location” or the clock check. Foreground only |
| Notifications | The optional “Remind me” reminders | Only when you switch reminders on |
| Vibration | Vibration cues and haptic feedback | When vibration is on in Settings |
| Receive boot completed | Reschedule your reminders after a restart, an app update or a change of the phone’s clock or time zone | Runs in the background briefly, uses no personal data |
The app does not request: internet access, network state, background location, a foreground service, exact alarms, wake lock, contacts, camera, microphone, storage or the advertising ID. While the chronometer is open, the app keeps the screen on, may show over the lock screen and may turn the screen on, using ordinary Android window settings. These need no permission and send no data.
7No internet access
Umbraday does not use the internet. The app removes the Android INTERNET permission from its manifest, so it technically cannot send data over a network. The eclipse data, place names, map and fonts are bundled in the app, and the calculations run on your phone.
Some things can still open outside the app, only when you tap or switch them on:
- the links to this Privacy Policy, the Terms of Use and the sources (NASA, the American Astronomical Society, GeoNames and others) open in your web browser;
- “Support” opens your e-mail app with the address
support@zydeno.comand the app name as the subject. Nothing else is filled in; - “Open in maps” passes the coordinates of the point you are looking at to the maps app you have installed (a
geo:link). That app may go online and has its own privacy policy. If no maps app is installed, the app only says so; - to produce the spoken cues, the app gives the fixed phrases (such as “Filter on now.”) and times to the text-to-speech engine installed on your phone, which turns them into audio files. The phrases never include your place name or coordinates. Whether your engine and voice work on the device or online is decided by your phone and that engine’s own privacy policy, not by Umbraday;
- when you print a contact card, the document goes to Android’s print service and the printer or print app you select.
From the moment your browser, e-mail app, maps app, speech engine or print service takes over, that app, not Umbraday, handles the connection.
8Reminders and notifications
If you switch on “Remind me”, Umbraday schedules a few local reminders with Android’s alarm service, for example a day before and again shortly before the eclipse. They are inexact on purpose (the app does not use exact alarms), are created and shown entirely on your phone, and contain only fixed text and eclipse times, not your location. Rehearsal mode sends no notifications. You can switch reminders off, or withdraw the notification permission in Android settings, at any time.
9Backup, import and deletion
- Export a backup (Settings → Your data) to a file you keep yourself, using Android’s system file picker, and import it again on this or another phone. The app does not need, and does not have, storage permission. After an import, the previous data can be restored with “Undo”.
- Delete places or other items inside the app at any time.
- Delete all data in Settings erases everything saved in the app on this phone (settings, places, journal, checklist, photo plan) and returns it to first launch. Deleted data cannot be recovered by us, because we never had a copy.
- Uninstalling the app removes its data from your phone. Files you exported yourself are not part of the app and stay where you saved them. Delete those separately.
10Data sources and attributions
All data is bundled inside the app. Umbraday does not download or look up anything while you use it, and nothing about you is sent to the owners of this data:
- Eclipse predictions courtesy of Fred Espenak, NASA/Goddard Space Flight Center, from eclipse.gsfc.nasa.gov. Local circumstances are computed on your device by Umbraday;
- Place names: GeoNames, licensed under CC BY 4.0. Selected and processed by Umbraday;
- Map data: Made with Natural Earth;
- Viewing guidance: NASA and the American Astronomical Society.
Umbraday is an independent app. It is not affiliated with or endorsed by NASA, the AAS or any government agency.
11Legal 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 | 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. |
| 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.
12Retention
Data stays on your device until you delete it or remove the app. We keep nothing, because we receive nothing.
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.
13Your privacy rights
Privacy laws in many countries give you rights over your personal data. Because Umbraday 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 (§9) and withdraw permissions in Android Settings. For data you have sent us, such as e-mails, write to support@zydeno.com.
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. 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.
14International users
Umbraday is available in many countries. The developer does not receive the data you keep in the app, so we do not transfer it anywhere.
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.
15Security
Your data is kept in the app’s private storage, which other apps cannot read on an unmodified Android device, and it is protected by your phone’s own lock screen and device encryption. Umbraday has no network access, so there is no connection that could be intercepted. Backup files you export are as protected as the place you put them. Protect your phone with a screen lock and keep your Android version up to date.
16Ads, purchases and future versions
Today. The current version of Umbraday 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. Ads would also require the app to connect to the internet, which the current version cannot do.
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 (§17).
17Children
Umbraday is a general eclipse guide. It is not directed to children under 13 and we do not knowingly collect any information from children. In fact the app collects no information from anyone. Children must be supervised by an adult whenever they watch an eclipse; see the eye-safety rules in the Terms of Use.
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.
18Changes to this policy
We may update this policy when we change the app (including any change described in §16), 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 (§19) 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.
19Version 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 | 2026-10-16 | First published. |
20Contact
- Developer (controller): Zydeno, the developer of Umbraday 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.