Pust — find calm through breath patterns
Pust watches nothing, measures nothing and sends nothing.
There is no account, no cloud, no advertising and no analytics. The app holds no internet permission, so it has no way to reach a network at all. Your patterns, the lengths you set for each phase, the record of sessions you have finished and your settings are written into the app's own private folder on the handset and remain there.
Below: what is kept and why one part of it deserves more care than it looks like it does, what the app is not allowed to touch, what this app is and is not, and what you may ask of the company behind it.
Pust is made and published by System Holding ApS, registered in Denmark at Brovangsvej 56, 3140 Ålsgårde, with Frank Daugaard Christensen answering for it. Under the General Data Protection Regulation the company is the controller for this app.
One thing worth saying before anyone wonders: the domain this page sits on does not carry the company's name. It is simply a domain the company holds, and the site on it is operated by System Holding ApS. Nothing more sinister than that, but it is the kind of mismatch that deserves an explanation rather than a shrug.
Write to pust@asrl.quest.
No name, no email address, no account, no device identifier and no advertising ID appear anywhere in that. Android keeps each app's private folder out of reach of every other app on the phone, and that folder is the whole of this app's memory.
Most of that list is settings. One line of it is not. A record of when somebody sat down to steady their breathing is a record of their difficult afternoons — the Sunday nights, the 3 a.m. entries, the week with six sessions in it and the month with none. Nobody writes that down about themselves on purpose, and yet an app that logs sessions is doing exactly that.
It is kept because the history is useful to the person it belongs to, and for no other reason. It never leaves the handset, it is never counted by anyone, and there is no mechanism by which it could be — which is a stronger statement than a promise to be careful with it.
Pust declares no internet permission, which Android enforces in the operating system rather than leaving to good conduct: an app without it cannot open a connection at all, whatever its code intends.
It also has no camera, no microphone, no location, no contacts, no photographs and no wider file access. That list is worth reading twice for an app of this kind, because breathing apps are widely assumed to be measuring something. This one is not. It does not listen to you breathe, it does not watch you with the camera, it reads no heart rate, it connects to no watch or band, and it holds no health or body-sensor permission of any sort. The shape on screen moves to the numbers you set, and it has no idea whether you are following it.
The haptic buzz at each phase change is the vibration motor, which requires no permission and reports to nobody.
Pust is a relaxation and focus aid. It is not medical advice, not a treatment, not therapy, and not a substitute for care from someone qualified to give it. It makes no claim to treat anxiety, panic, asthma, insomnia or anything else, and nothing in it is capable of assessing you.
Practical safety, because breath patterns are not entirely neutral. Long holds and fast patterns can make anyone light-headed. Sit or lie down to use them; never while driving or operating anything; never in or near water. Stop if you feel dizzy, or if your hands or face begin to tingle. If you have a heart or lung condition, are pregnant, or have ever fainted during breathing exercises, speak to a doctor before taking up a pattern.
And the thing that matters most. If breathing exercises are standing in for help you actually need, that is worth saying out loud to a person. In Denmark, Livslinien answers on 70 201 201, every day between 11:00 and 05:00, and the emergency number is 112. Elsewhere, your own local service is the right one to reach for. An app on a phone is not a plan.
Finished sessions add up to a visible streak, and streaks have a way of becoming obligations. This one is not meant to. Breaking it costs nothing, nothing is lost or reset elsewhere in the app, and no notification will arrive to point it out — the app sends none at all, because it has nothing to say to you between sessions.
If the count ever starts feeling like a thing you owe somebody, the honest answer is to stop looking at it. It was only ever a tally of some quiet minutes you gave yourself.
No ad network, no analytics library, no crash reporter, no attribution kit, no social sign-in. Nothing in this app is funded by observing whoever is holding the phone — which, given what the session log is, is the only arrangement that makes sense.
Should a later release ever add any of that, this page is rewritten before the release goes out and the Data safety entry in Google Play is corrected to match. Replacement wording already exists in the source of this page, commented out, so that nothing has to be improvised under pressure.
One thing happens above the app's head. Where backup to Google Drive is switched on, Android may copy the app's small data file — the session log included — into your own Google account alongside the backups of everything else installed. That copy belongs to you and sits under Google's terms rather than ours; the company has no account there and nothing to look at.
Given what the log contains, this is worth deciding on purpose rather than by default. Android's own settings turn it on or off, for the whole phone or for this app alone, and either answer is reasonable.
Installing is a transaction between you and Google, logged against your Google account. A developer afterwards sees totals in a console: installs by country, the spread of Android versions, how a rating is moving. No individual row sits beneath those numbers for anyone here to open, and nothing in them touches a session.
Google's own part runs under Google's privacy policy at policies.google.com/privacy.
Everything is in one folder, so there is one action and nobody to ask. Uninstalling Pust removes the patterns, the session log and the settings together. Android's app settings will also clear the app's storage while leaving it installed, which empties the history and returns the app to its first run.
Both are immediate and neither can be undone, and neither needs anything from us, because no second copy was ever made anywhere.
This is the only part of the page about data that actually arrives somewhere. An email leaves the company holding an address and whatever the message contains, for as long as the matter is live and a short while after in case it returns, and the thread is then deleted.
It is used to reply and for nothing else — no list, no onward sharing, no marketing. The lawful basis is legitimate interests, in answering people who write. Nothing in an email can be joined to anything in the app, since the app holds no identifier for it to be joined to. Ask for an exchange to be deleted and it will be.
The General Data Protection Regulation applies in Denmark alongside databeskyttelsesloven. Together they let you ask what personal data is held about you, receive a copy, have it corrected or erased, limit what is done with it, object to that use, and take it elsewhere in a portable form. Pointed at the app, those requests describe an empty shelf. Pointed at the mailbox above, they work in full, cost nothing, and are answered within a month.
Send them to pust@asrl.quest. Denmark's supervisory authority is Datatilsynet, at datatilsynet.dk, which will hear a complaint whether or not you have raised it with us first. Anyone living elsewhere in the EEA may go to their own national authority instead.
One date appears on it, under the title, and that is the edition in force. Where something genuinely alters what happens to data — any collection at all, any third-party component, anything leaving the phone — the order is fixed: this page is rewritten first, the Data safety declaration in the Play Console is corrected in the same sitting, and the release responsible follows after both.
A sentence rewritten for clarity is not that, and arrives with nothing but a newer date.
System Holding ApS
Brovangsvej 56, 3140 Ålsgårde, Denmark
Responsible: Frank Daugaard Christensen
Du er velkommen til at skrive på dansk.
© 2026 System Holding ApS