Privacy
Umbro — this website and the iPhone and iPad app — is operated by CTT Apps LLC.
There are no accounts, and nothing you do here is sold. The app carries advertising on two of
its screens, described below; nothing about which eclipse you are looking at, or where you
searched, is sent to the advertiser. The astronomy runs on your own device; this page lists
everything that does leave it, and what happens to it.
Last updated 22 October 2026.
What stays on your device
All the astronomy — eclipse discovery, shadow geometry, contact times, obscuration, the path
of totality and the star background — is computed on your device. None of it is sent anywhere.
The website keeps a few things in your browser's local storage: the location you are using
(umbra.loc), the anonymous ID described below (umbro.pid), when it last
checked in (umbro.ping), and which eclipses you asked to be reminded about
(remindEvents). A location you picked yourself is kept until you change it; one that
was detected automatically is discarded after 24 hours. Clearing your browser's data for this
site removes all of it.
Your location
If you allow it, your device's precise position is used for the calculations — on the device.
So that the page can name a town rather than show a pair of decimals, the position is
rounded to about a kilometre and sent to a place-name service: OpenStreetMap's
Nominatim on the website, Apple's geocoder in the app. Searching for a place sends the text you
type to the same services.
On the website, if you don't allow precise location, the site asks a third-party service to
turn your IP address into an approximate city — ipwho.is, geojs.io and ipapi.co, tried in that
order, each under its own privacy policy. That request necessarily reveals your IP address to
whichever answers. Allowing precise location, or typing a place into the search box, avoids it.
What Umbro's own server receives
Umbro runs a server at umbro.app. This is everything it is sent:
- Weather and elevation. Your position, rounded to about a kilometre, so
umbro.app can fetch time zone, ground elevation, cloud records and forecasts from Open-Meteo
and OpenWeatherMap on your behalf. Those services see umbro.app, not you. The cloud map sends
the area you are looking at. Answers are cached by rounded position so neighbours share them.
- A daily anonymous check-in. At most once a day the website and the app send:
a random ID that this browser or this copy of the app made up for itself; the version; the
device model (app) or the first 48 characters of the browser's user-agent (website); the town
you are looking at and its position rounded to about 11 km before it is sent;
and, from the app only, whether reminders are on and how many times a few features have been
used. It is not linked to your name, email or Apple account, and your IP address is not
stored with it. Each day's rows are deleted after 60 days; only a total for the day is kept.
In the app the ID is held in the device's keychain, which means it survives deleting and
reinstalling the app — that is so a reinstall is not counted as a new person.
- Crash and performance summaries (app only): the counts of crashes and hangs,
launch time and the iOS and app versions that iOS collects, sent with the same random ID.
Deleted after 60 days.
- Page views (website). The server counts which page was opened, on what day,
and the domain of the website that linked to it. To tell a reload from a new visitor, it keeps
a one-way hash of the day, your IP address and your browser's user-agent under a secret key;
because the day is inside the hash, two days' visits cannot be connected, and these hashes are
deleted after 7 days. Your IP address itself is not stored. Only the totals are kept. Clicks
on the website's App Store links are counted the same way before you are passed to Apple.
- Errors. When a page hits a bug, the browser posts the error
message, the stack trace and which page it happened on. It goes to umbro.app, not
to the error-tracking service, precisely so that your address never reaches them —
the server forwards the report onward to Sentry without it. Query
strings are stripped on the way, because the weather requests carry coordinates in
theirs. No error report identifies you, and the page sends at most five per visit.
- Reminders, only if you turn them on. The address your browser's push service
gives this site, or the app's notification token; your precise position and
time zone; and which eclipse. Precise because near the edge of a path a kilometre decides
whether you see totality. Used only to send those reminders, and deleted two days after that
eclipse, when you turn reminders off on the website, or as soon as the push service reports
the address is no longer valid — which happens after you delete the app or block
notifications. Reminders are delivered through Apple's, Google's or Mozilla's push service.
Other services your device contacts
- Map tiles — Esri on the website, built on OpenStreetMap data; Apple in the
app — whenever a map is on screen. These carry your IP address and the area you view.
The website used CARTO's tiles until October 2026, when they began requiring an API key.
- The MapLibre mapping library, which the website loads from the unpkg.com
content network. That request reveals your IP address to unpkg and its CDN, as any download
does; the library itself collects nothing.
- Place names and search, as described above.
- The App Store, if you follow a link to it.
The iPhone app is the one exception to "nothing goes to a third party directly": when it
crashes, it sends the stack trace straight to Sentry, which reveals its IP
address as any network request does. The report carries the device model, the iOS and app
versions and where in the code it failed — not your location, not an identifier, and no
screenshot. The website's error reports do not work this way; they go through umbro.app
as described above.
There are no other network calls: no advertising or analytics companies, no trackers, no
fingerprinting scripts. The error reporting above uses no third-party script — it is a
few lines served from this site like everything else here.
Server logs
umbro.app is hosted on Railway on behalf of CTT Apps LLC. Like any web host, its
infrastructure may record standard request metadata — IP address, timestamp, requested path,
user agent — for delivery and abuse prevention. CTT Apps LLC does not analyse those logs and
builds no profiles from them.
Advertising in the app
The iPhone and iPad app shows advertising in two places and nowhere else: at the foot of the
Upcoming eclipses list, and at the foot of the About screen.
There is deliberately none on the tracker, the path, the camera, or any screen you would be
looking at during an eclipse — an advertisement has no business covering guidance about when
it is safe to look at the Sun.
The ads come from Google AdMob. To fill them, Google receives your device's
advertising identifier, its model, the app and iOS versions, your IP address and a coarse idea
of where you are. It does not receive your precise location, the place you searched for, or
which eclipse you were reading about. What Google does with it is covered by
Google's own
policy.
Whether those ads are personalised is yours to decide, and you are asked twice. In the
UK, the EEA and Switzerland a consent form appears before any ad is requested, and refusing it
is a button of equal standing with accepting; you can reopen it at any time. Everywhere,
iOS asks separately for permission to track, and declining it is the end of the matter. If you
decline either one you still see ads — they are simply chosen without reference to you, and
nothing else about the app changes.
This website carries no advertising today. If that changes, this page will say so before it
does, and a cookie notice will appear with it.
Your choices, and contact
You can use Umbro without allowing location, by searching for a place instead. Clearing this
site's data in your browser removes everything it stored. Turning reminders off on the website
deletes them from the server at once; in the app, turning notifications off in Settings stops
them, and the server forgets the token when the push service reports it invalid.
Because nothing is linked to a name or an account, there is usually nothing we can look up about
you — but questions about this policy, or about any data you think Umbro holds, are welcome at
umbro@cttapps.com.
Children, and changes
Nothing here is directed at children specifically, and no personal information is knowingly
collected from anyone. If this policy changes, the updated version will appear on this page with
a new date at the top.
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