The company
Registered in Denmark, built one app at a time
The publisher is System Holding ApS, at Brovangsvej 56, 3140 Ålsgårde, and Frank Daugaard Christensen answers for what goes out under it.
A holding company with a breathing app on Google Play is an unusual line on a store listing, so it is set out here rather than left to be worked out. The software is the company's own, and it shares nothing with whatever else the company does but an address.
Nothing behind the app
What an app needs to remember goes into its own private folder on the phone, which Android keeps sealed off from everything else installed. No account, no identifier, no counted events, no advertising library.
So there is no database to lose, nothing to pass on, and no service whose shutdown takes the app with it.
The app
Pust
Find calm through breath patterns
com.rolig.pust
A quiet companion for slowing down. Choose a pattern — relaxed, box breathing, or a longer wind-down — and a soft shape grows and falls to lead each breath, so you follow the motion instead of counting in your head.
Every phase can be tuned: how long in, how long held, how long out, how long the pause. Patterns of your own sit beside the built-in ones, and you choose how many rounds a session runs. A gentle haptic can mark each change if you would rather close your eyes, and a soft cue can keep the rhythm. Finished sessions are logged quietly so a run of calm moments is visible over days and weeks — a record, never a demand. English and Danish, offline, no account, no advertising.
Pust on Google PlaySaid plainly, because it matters more than the feature list. Pust is a relaxation and focus aid. It is not medical advice, not a treatment and not a substitute for care. Long holds and fast patterns can make anyone light-headed, so breathe sitting or lying down, never while driving, never in or near water, and stop if you feel dizzy or your fingers tingle. If you have a heart or lung condition, are pregnant, or have ever fainted during breath exercises, ask a doctor before taking up a pattern. And if breathing exercises are standing in for help you actually need, that is worth saying out loud to someone: in Denmark, Livslinien answers on 70 201 201 daily between 11:00 and 05:00, and the emergency number is 112.
Why you have lungs at all
Oxygen moves through still fluid by diffusion — molecules jostling at random until, on average, they have spread. The spreading is described by one unforgiving relation: the time needed goes as the square of the distance, t = x² ⁄ 2D. Over a micrometre that is quick enough to be invisible. Over a centimetre it is already hopeless, and over the length of a body it is absurd. Everything about the architecture of breathing — the branching, the enormous surface, the pump, the circulation — exists to keep every diffusion distance in the body down to the scale where that formula is still kind. The panel works it out for whatever distance you like.
6.61 hfor oxygen to cross that gap
1.0 cmthe gap you chose
65 µmhow far it gets in one second
130 µmhow far in the four seconds of an unhurried breath
4×the cost of doubling any distance
7.54 yearswhat one metre would take
Not on this panel: nothing to breathe along with. No circle, no count, no timer and no pattern — this is a statement about random walks, not an exercise, and it has no opinion about how anyone should breathe.