Privacy Policy

Last updated: 22 July 2026

Caelo is made by Paul Smith, an independent developer in Australia. You can reach me at hello@caelo.today about anything on this page.

I’ll keep this short and specific, because a privacy policy that hides behind lawyer-speak isn’t telling you anything.

The short version

Caelo has no accounts, no login, and no server of mine. Everything you create in the app — your sky profile, your horizon, your favourites, your session plan — is stored on your iPhone and nowhere else. I can’t see it, because it never reaches me.

Two things do leave your device, and only these two:

1. Your observing coordinates go to a weather service, so Caelo can tell you whether tonight is worth going outside for.
2. Apple handles your payment if you buy the Pro unlock.

That’s the whole story. The rest of this page is the detail behind it.

What Caelo stores on your device

All of this lives in Caelo’s own storage on your iPhone. None of it is uploaded to me.

• Your sky profile — the coordinates of your observing site, the horizon outline you captured, and the name you gave the profile.
• Your saved locations — coordinates and the names you typed for them.
• Your favourites and your session plan — which objects from the catalogue you’ve starred or planned to observe.
• Your telescope selection — which of the built-in telescope presets you chose.
• A cached weather forecast for your site, so the app works when you’re out of signal.
• Calculated results — precomputed visibility data, derived from the above.
• App settings — whether you’ve finished onboarding, and your light/dark appearance choice.

Two of these are free-text fields you fill in yourself: your profile name and your location name. Whatever you type there is stored as you typed it, next to that site’s coordinates. If you’d rather not have your home address sitting in a field called “Location name”, call it something else — “Home” or “Back garden” works just as well, and the app never needs the real thing.

What leaves your device

Weather

To tell you tonight’s cloud cover, Caelo asks Open-Meteo for a forecast. Before that request leaves your phone, Caelo rounds your coordinates to about a kilometre (two decimal places). The forecast is identical at that precision, so your exact spot — your backyard, your driveway — is never transmitted; only the neighbourhood-level pair is. The request contains those rounded coordinates and nothing else — no name, no device identifier, no account, no advertising ID. There is nothing in the request that identifies you or your phone.

The full-precision coordinates you captured stay on your device, where the astronomy maths genuinely needs them.

As with any request to any website, Open-Meteo will also see your device’s IP address, which is a rough indicator of where you are. That’s how the internet works rather than a choice Caelo makes, but you deserve to know it happens.

Open-Meteo is an independent weather service with its own privacy terms, which govern what they do with a request once it reaches them.

The forecast that comes back is cached on your device so the app still works when you have no signal.

Payment

If you buy the Caelo Pro unlock, Apple handles the entire transaction. Caelo tells Apple which product you’re buying and Apple tells Caelo whether you own it. Your payment details, your Apple ID, and your purchase history are Apple’s to handle under Apple’s privacy policy — they never pass through Caelo, and I never see them.

Nothing else

To be explicit about the things Caelo does not do:

• No analytics. No usage tracking, no event logging, no session recording.
• No crash or diagnostic reporting of any kind sent off your device.
• No advertising, no ad identifier, no third-party advertising SDKs.
• No tracking, as Apple defines it — Caelo never links your data to anything from other companies’ apps or websites, and never shares it with data brokers.
• No account, no sign-in, no cloud sync of your data by me. There is no Caelo server holding your information, because there is no Caelo server.
• No selling of anything to anyone. There’s nothing to sell, and I wouldn’t.

Permissions Caelo asks for, and why

Caelo asks for three things, and only uses them for what it says.

Location — Caelo needs to know where you’re standing to work out what’s visible from there and to fetch your local weather. Caelo requests location only while you’re using the app, never in the background. Your precise location is read while you capture a sky profile, then saved with that profile; after that, the app uses the saved coordinates rather than tracking you.

Camera — used only as a live viewfinder while you mark the trees and rooftops on your horizon, so you can see what you’re pointing at. Caelo takes no photographs and records no video. No image or camera frame is ever saved, exported, or read by the app — the only thing kept from a horizon capture is a list of angles: how high your obstructions are, and in which direction.

Motion sensors — used to know which way your phone is pointing while you’re marking those obstructions. Nothing more.

You can withdraw any of these at any time in iOS Settings. Caelo will lose the matching capability, but it won’t misbehave.

Backups

Because Caelo’s data lives in your app’s normal storage, it’s included in your iPhone’s own backups — encrypted iCloud or computer backups, run by Apple’s settings, not by Caelo. That backup belongs to you and Apple; I have no access to it and no way to reach it.

Deleting everything

Settings → Delete All Data erases every piece of it: your profiles and their coordinates, your locations, favourites, session plan, telescope choice, the cached weather, and every calculated result. The app returns to first-run state. It’s immediate, it’s permanent, and it doesn’t need my involvement — there is no copy anywhere for me to delete.

Deleting the app from your iPhone removes it all too.

Two honest footnotes. Your Pro purchase isn’t erased, because it isn’t Caelo’s to erase — Apple holds that entitlement against your Apple ID, which is what lets you restore it on a new phone. And deleting your data doesn’t revoke the iOS permissions you granted; those live in iOS Settings, where you can turn them off yourself.

Children

Caelo isn’t directed at children, and doesn’t knowingly collect anything from them. It has no accounts and no way to identify who’s using it.

Your rights

If you’re in the European Economic Area or the UK, the GDPR gives you rights over your personal data: to access it, correct it, delete it, take it with you, and object to how it’s used.

Caelo’s design answers most of these without anyone’s involvement, because the data is on your device rather than mine: you can see it in the app, edit it, export nothing because there’s nowhere it went, and delete all of it with one button. Where I process anything, the legal basis is the legitimate interest of making the app do the one thing you opened it to do — and for location, the permission you granted in iOS, which you can withdraw at any time.

If you believe I’ve mishandled something, you’re entitled to complain to your local data protection authority. I’d appreciate the chance to fix it first — hello@caelo.today.

Australian users: the same protections apply under the Privacy Act 1988 and the Australian Privacy Principles.

Data outside your country

The only data that travels is the rounded coordinate pair sent to Open-Meteo, which is served from Europe. Because that request carries nothing identifying you, this transfer is minimal by design.

Changes to this policy

If Caelo ever starts doing something new with your data, this page changes first and the date at the top changes with it. If a change is significant, I’ll say so in the app’s release notes rather than quietly editing the page.

Contact

Paul Smith — hello@caelo.today

Caelo is an independent app made in Australia.