Effective date: 23 October 2026. This policy replaces the version dated 8 March 2026.
Lungy is made by Pi-A Creative Systems Ltd ("Pi-A", "we", "us"), a company registered in England and Wales, company number 12832544, based in London, United Kingdom. Pi-A is the data controller for the personal data described in this policy. You can reach us about anything in it at hello@lungy.app, with "Privacy" in the subject line.
This policy covers the Lungy app and the website at lungy.app. It should be read with our Terms of Use and our Medical Disclaimer.
1. The short version
2. What happens on your device
Microphone. Lungy listens to recognise when you breathe in and out. The sound is analysed as it arrives and discarded. No audio is recorded, streamed, transmitted or stored, unless you have joined a research study and agreed to that in writing (section 7).
Camera and face tracking. If you choose to use the camera, Lungy tracks the position of your face to help you hold the phone in the right place and to judge how well your breathing was detected. On phones with a TrueDepth camera it uses that depth sensor. No photos, video or depth data are recorded or stored, and no face data leaves your device. The tracking data exists only while the camera screen is open and is discarded when it closes. You can turn the camera off at any time in Settings.
Breathing results and progress. After each exercise, Lungy stores numerical results such as how many breaths you took, how long they lasted and how steady they were, together with your streaks and history. This data stays on your device and is encrypted. Deleting the app deletes it.
Apple Health. If you allow it, Lungy writes each session to Apple Health as mindful minutes, and can read your heart rate, resting heart rate, heart rate variability, respiratory rate, blood oxygen, sleep and step data to show them alongside your breathing. Health data is read on your device only. We do not upload it, and we never use it for advertising or share it with anyone. You control this in the Health app at any time.
3. Your Lungy identifier
When you first open Lungy, the app creates a random identifier for your installation. It is not derived from your name, email, phone number or Apple ID, and we have no way to connect it to you. Every service in section 4 receives data under this identifier so that we can, for example, match a purchase to the app that made it. Deleting and reinstalling the app creates a new identifier and disconnects the old one from your device.
4. What leaves your device, and why
The table below lists every service that receives data from the app or the website, what it receives, why, our legal basis under the UK GDPR, and how long we keep it. Breathing results, audio and camera data are never among them.
| Purpose | Data | Service and location | Legal basis | Kept for |
|---|---|---|---|---|
| Handling subscriptions and purchases | Your Lungy identifier, purchase and subscription status, product and price, country. Payment details go to Apple and never reach us. | RevenueCat (United States) | Contract | Life of the subscription plus 7 years for tax and accounting records |
| Understanding how the app is used and finding bugs | Screens visited, features used, exercise started and completed, app version, device model, operating system, language and country, approximate region from your IP address | Mixpanel (United States) | Legitimate interest in improving Lungy | 3 years |
| Checking the quality of the app's screens | Recordings of some app screens, with personal information obscured, so we can check the interface works and reads well. Your breathing results and the camera view are not captured. | Mixpanel Session Replay (United States) | Legitimate interest | 30 days |
| Crash reports | Crash logs, device model, operating system, app version, the state of the app when it crashed | Google Firebase Crashlytics (United States) | Legitimate interest in a working app | 90 days |
| Knowing which advertising or link brought you to Lungy | Your Lungy identifier, device and operating system details, IP address, the fact that you installed and opened the app and completed the tutorial. We do not request your advertising identifier. | Adjust (Germany) and Meta's app events service (United States) | Legitimate interest in measuring our marketing | Adjust: 2 years. Meta: per Meta's data policy |
| Sending notifications you have turned on | A push token for your device, time zone, language, app version | OneSignal (United States) | Consent, through your notification permission | Until you turn notifications off or delete the app |
| Testing improvements before releasing them to everyone | Your Lungy identifier and which version of a feature you were shown | GrowthBook (United States) and our own database on Supabase (European Union) | Legitimate interest | 2 years |
| In-app surveys and feedback | Your answers, any text you type, whether you have a subscription, how many exercises you have done, days since install, language and app version. Please do not type personal details into free-text boxes. | Our own database on Supabase (European Union) | Consent, by choosing to answer | 3 years, then deleted or anonymised |
| Our mailing list, if you sign up on the website | Your email address | Web3Forms (United States) to deliver it to us | Consent | Until you unsubscribe |
| Website analytics | Pages visited, approximate region, browser and device type, through Google Analytics cookies | Google Analytics (United States) | Consent, through the cookie notice on the website | Up to 14 months |
These companies process data only on our instructions under written agreements. Where data goes to the United States we rely on the UK Extension to the EU-US Data Privacy Framework or on standard contractual clauses approved for the UK.
5. What we never do
6. How we use the data we do receive
7. Research
We may invite you to take part in research into breathing and lung health. Taking part is always a separate, specific choice. Before you join a study we tell you who is running it, what will be collected, where it will be stored and for how long, and you can withdraw at any time, which stops any further collection. Only if you join a study, and only with your explicit consent, may the app record audio from breathing exercises and send it, with the camera's position measurements, to the study. Research data is kept separately from the data in section 4. Where a university or hospital runs a study, it becomes responsible for the data it receives and we will tell you how to contact it. Published results use anonymous, aggregated data only.
8. Children
Lungy is not directed at children. You must be 16 or over to use it, or have a parent or guardian's permission if you are younger and your local law allows it. If you believe a child has used Lungy and data has reached us, email hello@lungy.app and we will delete it.
9. Your rights
You have the right to ask for a copy of the personal data we hold, to have it corrected or deleted, to restrict or object to how we use it, and to withdraw any consent you have given. Because Lungy has no accounts, most of your data is on your device and you control it directly: deleting the app deletes your breathing results and progress and disconnects your identifier from your device. For data in section 4, email hello@lungy.app with your request. If you can tell us your Lungy identifier, found in Settings, we can locate and delete the data held under it. We answer within one month.
You can also complain to the Information Commissioner's Office at ico.org.uk, or to your local data protection authority.
10. Security
Data on your device is encrypted by your phone; please set a passcode. Data in transit is encrypted. Data we hold is stored with the providers named above under access controls, and we review who has access. No system is perfectly secure, and if a breach affects you we will tell you and the regulator as the law requires.
11. If Lungy changes hands
If Pi-A or the Lungy app is sold, merged, reorganised or becomes insolvent, personal data may be transferred to the new owner as part of that change. The new owner may use it only for the purposes in this policy, under the same protections, unless they ask for and receive your fresh consent. We will tell you before any such transfer, and you can delete your data beforehand.
12. Changes to this policy
We review this policy at least once a year. If we make a change that matters to you, we will tell you in the app before it takes effect. Previous versions are available on request.
13. Contact
Email hello@lungy.app with "Privacy" in the subject line. Pi-A Creative Systems Ltd is registered in England and Wales, company number 12832544; its registered details are on the Companies House register.