smoggyapp is a citizen-science app. It is built privacy-first: you can observe and submit without giving us your name or email, and your photos are never stored. This page explains the data we handle, who receives it, and why.

Who is responsible

smoggyapp, operated from Greece, is the data controller under the GDPR. Contact: support@smoggyapp.com

What we collect

• Approximate location — rounded to about a 1 km area (2 decimal places) before it is stored or sent anywhere. We use it to match the aircraft passing overhead with your sky and to fetch the weather where you are. It is stored anonymously and is never linked to your identity.
• Observation data — for each sighting: the weather snapshot, air-quality readings, the upper-air atmospheric profile, the AI contrail result and its confidence score, and timestamps. Anonymous.
• Device orientation at the moment of the photo — compass heading, tilt and rotation. These are sensor angles, needed to work out where in the sky you were pointing. They are not a device identifier and cannot be used to recognise your phone.
• Public flight data — the aircraft near you at that moment, taken from public ADS-B broadcasts. This is data about aircraft, not about you.
• An anonymous ID — a random identifier created automatically so your own observations, level and streak stay together. It is not linked to your name or email. Under the GDPR this counts as personal data, so it is covered by your rights below.

What we never collect

• Your photos — sent to our AI provider for instant analysis, then immediately discarded. The image itself is never stored or retained after analysis.
• Your name, email, or any sign-in details — observing never requires them.
• Device identifiers or advertising IDs — never, in any form.
• Your exact GPS position — it never leaves your phone at full precision. Everything sent out or stored is rounded first: to about 1 km for weather, air quality and the aircraft search, and to about 10 m for the one calculation that needs it — working out where in the sky your camera was pointing. That rounded figure is used for the calculation and is never stored.

The shared map

When you submit an observation, the app may add an entry to a public map that anyone can read — an approximate location, a short label, a timestamp and your anonymous ID.

Your exact position is never published. Every entry is shifted by a small distance (roughly 1–2 km) before it's published, using a method designed so that your real location can't be worked out even by combining many of your entries together over time. If you post from a variety of different places rather than always the same spot, that adds even more uncertainty on top — there's no single, tight cluster of entries for anyone to zero in on.

Nothing else from your observation reaches the map: no weather, no air quality, no upper-air profile, no flight details, no confidence score. You can remove your entries at any time with Delete my data.

The exact method used is documented in our source code and can be provided to data protection authorities on request, to verify GDPR compliance.

Why we are allowed to do this (legal basis)

Location is used only after you tap Allow location — that is your consent (Art. 6(1)(a)), and you can withdraw it at any time in your device settings (the app still works for photos and AI). We also apply basic anti-abuse limits to keep the service running, which is our legitimate interest (Art. 6(1)(f)). Research use of the anonymised dataset falls under Art. 89.

Where your data is stored, and who else receives it

Anonymous observations are stored in Google Firebase (Firestore), running on Google Cloud infrastructure. We also use these providers, which receive only what is listed:

• Roboflow — the photo, for analysis only. Not stored.
• Open-Meteo — your approximate (rounded) location, for weather and air quality.
• adsb.fi and the OpenSky Network — your approximate (rounded) location, to find nearby aircraft.
• Netlify — our own hosting. It receives your IP address as part of normal web hosting and anti-abuse rate limiting, and it runs the code that works out the trail's position in the sky. For that calculation it briefly receives your rounded location and the camera angles. Neither is written down or kept.
• OpenFreeMap / OpenStreetMap, NASA GIBS, ECMWF Copernicus — your IP address, when map tiles or layers load.

Where a provider is outside the European Economic Area, the transfer is covered by the European Commission's Standard Contractual Clauses or an adequacy decision.

Sharing

We do not sell personal data, and we run no ads or third-party trackers. Anonymised and aggregated observations — which cannot be traced back to you — may be published or licensed for scientific research into contrails, clouds and weather.

How long we keep it

• Observations — kept for as long as the research dataset exists. Their scientific value is precisely that they can be compared across years.
• Shared-map entries — removed 30 days after they are posted. The clean-up runs on your own device the next time you open the app, so an entry from a phone that is never opened again may sit there longer. Delete my data removes all of yours straight away, whatever their age.
• Photos — not kept at all.

Deleting your data removes everything linked to your anonymous ID immediately, whatever its age.

Age

smoggyapp is not directed at children. If you are under 16, please do not use the app without a parent or guardian's involvement. We do not knowingly collect data from children below that age; if you believe we have, write to support@smoggyapp.com and we will delete it.

Data & credits

Weather & air-quality data by Open-Meteo.com (CC BY 4.0). Flight data via the OpenSky Network and adsb.fi.

Atmospheric composition map layers contain modified Copernicus Atmosphere Monitoring Service (CAMS) information (ECMWF). Neither the European Commission nor ECMWF is responsible for any use of this information.

Satellite imagery courtesy of NASA EOSDIS Worldview / GIBS, part of the NASA Earth Science Data and Information System (ESDIS).

Base maps © OpenFreeMap & OpenStreetMap contributors.

Your rights

Under the GDPR you can access, correct or delete your data, object to processing, and ask for a copy in a portable format. The fastest route is built into the app: open the left menu → Your data → Delete my data. This erases every observation linked to your anonymous ID, every entry you have published to the shared map, your stats, and the anonymous account itself — instantly, with no email required.

One limit you should know: once an observation has been included in an anonymised research dataset, it can no longer be linked to you — and for that reason it cannot be removed from that dataset.

Questions or complaints: support@smoggyapp.com. We answer within one month. You also have the right to lodge a complaint with your national data-protection authority — in Greece, the Hellenic Data Protection Authority (dpa.gr).

Changes to this policy

If we add new features that change what we collect or who receives it, we will update this page before that change goes live.

Contact

Questions or requests: support@smoggyapp.com

By using smoggyapp you agree to these terms. If you do not agree, please do not use the app.

What smoggyapp is

smoggyapp shows you real flight and weather data so you can observe contrails and judge the sky for yourself. It is an informational, citizen-science tool — not a safety, navigation, aviation, or official scientific service. We do not guarantee that the data is accurate, complete, or always available.

Acceptable use

• Use the app for your own lawful, personal observations.
• Do not abuse, overload, scrape, or reverse-engineer the service.
• Do not submit fake, misleading, or harmful content.

Rate limits

To keep smoggyapp available for everyone and prevent abuse, we apply limits to how often requests can be made. This protects the service and is part of running it responsibly.

Support

smoggyapp is offered at no charge at present and is supported by voluntary contributions. We may change what is offered at no charge, or introduce paid features, at any time. A contribution is a gift, not a purchase: it is not refundable, buys no goods or services, and unlocks no features — every user gets the same app.

A paid Pro tier is planned for the future. Supporting the project now does not grant access to it.

Intellectual property

The smoggyapp app, name, logo, and content are owned by smoggyapp. The anonymous observation data may be used for research.

Data sources & attribution

smoggyapp shows data produced by third parties. We credit them here as their licences require:

• ECMWF — forecast and atmospheric data, used under CC BY 4.0. Values shown in the app are calculated by smoggyapp from ECMWF data and are therefore modified from the original. Neither ECMWF nor its licensors is responsible for any use of this data.
• Copernicus Atmosphere Monitoring Service (CAMS), implemented by ECMWF — aerosol and air-quality layers. Neither the European Commission nor ECMWF is responsible for any use of this information.
• NASA EOSDIS GIBS — satellite cloud imagery.
• Open-Meteo — weather and air-quality API, CC BY 4.0.
• adsb.fi and The OpenSky Network — aircraft position data, used under their non-commercial terms. Aircraft identifiers are not displayed and are not included in any export.
• OpenFreeMap and OpenStreetMap contributors — base map tiles.

These organisations do not endorse smoggyapp and are not responsible for it.

Disclaimer & liability

The app is provided “as is”, without warranties of any kind. We are not liable for any decisions you make based on the information shown.

Changes

We may update these terms. Continued use after an update means you accept the new version.

Contact

Questions: support@smoggyapp.com