Show HN: I'm a doctor and built a responsive breathing app for anxiety and sleep

[lukko]

Hey HN!

I’m an NHS doctor and the founder of Pia (https://www.piahealth.co) which developed Lungy (https://www.lungy.app). Lungy is an iOS app that responds to breathing in real-time and was designed to make breathing exercises more engaging and beneficial to do. It’s been two years since Lungy launched (here’s the original ShowHN: https://news.ycombinator.com/item?id=34534615) and it's had a huge update and complete redesign. We rebuilt the whole app, and added a real-time 3D soft body solver which gives some really cool interactions like blobs / objects that inflate as you breathe. We also made a version for Vision Pro, called 'Lungy Spaces'.

My background is as a surgical trainee and I started building Lungy in 2020 during the first COVID lockdown in London. During COVID, there were huge numbers of patients coming off ventilators and patients are often given breathing exercises on a worksheet and disposable plastic devices called incentive spirometers to encourage deep breathing. This is intended to prevent chest infections and strengthen breathing muscles that have weakened. I noticed often the incentive spirometer would sit by the bedside, whilst the patient would be on their phone – this was the spark that lead to Lungy!

Since making the first version we’ve made exercises fully customisable (you can dial in exact timings for each breath phase), added new breathing indicators, learning modules, e.g. self-care for anxiety symptoms, and lots of new visuals. The free version gives you access to a new breathing exercise each day, whilst premium unlocks the full library of exercises, exercise data and visuals..

The visuals are mostly built using Metal (a couple use SpriteKit) and there are lots to choose from - boids, cloth sims, fluid sims, a hacky DLA implementation, rigid body + soft body sims - each one reacts to breath and touch. The audio uses AudioKit with a polyphonic synth and a sequencer plays generated notes from a chosen scale (you can mess around with the sequencer and synth in Settings/Create Music). The nice thing about the visuals + audio being generative is that the download size is relatively small with no other downloads. We’re still working on improving the breath detection, using ML - currently, it uses microphone input, with optional camera input to guide positioning.

We’re also close to finishing the medical device version - http://lungy.health - designed as a pulmonary rehab platform for patients with asthma, it should hopefully undergo early trials in the UK in 2026.

Thanks for reading - would love to hear any feedback!

https://www.lungy.app

Lungy Version 2 here: https://apps.apple.com/app/apple-store/id1545223887

[abcd_f]

Why is it a subscription?

* Why am I in gray? It's a reasonable thing to ask about an app with no server-side expenses.

[lukko]

Why is there a premium version? Lungy did take a long time to make and there are ongoing costs even if no server currently. This work was pre-LLM - a lot of care and attention went into making it and it would not be viable in any way without some kind of monetisation.

That said, there is a lifetime access option, so no subscription, and the free version is good too.

[jamil7]

Serious question, have you tried to launch and sustain a consumer mobile business in the last 5 years? I have and the paid up front model is very difficult to make work. As much as users say they want to pay once, what they actually want is to pay once and receive a steady stream of features, improvements, updates for new iOS versions etc. The idea that there are no server-side expenses doesn't make a project like this static, iOS itself is a moving target for developers before you factor in user expectations from modern software.

[QuantumGood]

$40 for lifetime access includes regular updates.

[spondylosaurus]

Any plans for an Android version? I'd love to try it, but I'm on the other side of the Apple App Store wall :(

[lukko]

Yes, we would do this for any medical device version - there is a hurdle of porting over all the shader code, but actually with LLMs it should be much easier. I'm not sure whether to go fully Android native, or cross platform though..

[its-summertime]

There are about 4-5 breathing apps on F-Droid if you don't mind something a bit less.

[sgt]

My experience is that Android users tend not to want to spend money on apps that much, even IAP is tricky. So sometimes it's not worth the hassle to go multi platform.

[fao_]

A friend of mine was working on this exact thing about 2 years ago in collaboration with the NHS before Google pulled half their stack out from under them. Incredibly sad on the whole but glad that it's happening in some form.

[lukko]

Ah was it based on SpiroSmart at all? It's a smartphone tech Google purchased in around 2017 [0].

Yep, it has been tricky to get over the line as a medical device and used in the NHS, hence the focus more on wellness initially.

[0] https://www.healthcareitnews.com/news/alphabet-acquires-seno...

[tetha]

> We’re also close to finishing the medical device version - http://lungy.health - designed as a pulmonary rehab platform for patients with asthma, it should hopefully undergo early trials in the UK in 2026.

This sounds great. Maybe there could also be something to help people support an asthma attack, or a beginning one. Breathing can be hard folks.

Mostly saying this, because this brought up memories of a situation where a woman on a bus had the beginnings of an asthmatic attack and then realized she didn't have her inhalator on her and started to stress out. The poor bus driver had no idea what do to and also started to panic. So I ended up just being here, helping her remember techniques like the coachman seat, pursed lip breathing, all while I was kinda fighting that on one hand, my inhalator is an entirely standard inhalator, but on the same time, handing out prescription medication like that can be really, really dangerous.

Give this[1] a read, it's good to now :)

1: https://www.pari.com/int/blog/breathing-excercise-asthma/

[lukko]

Sounds like you did a really great job - seeing an asthma attack unfold can be scary, and you were right to be very cautious in sharing your medication.

So, the health version will more be a collection of simple interventions which hopefully improve symptom control and quality of life, more day-to-day control than in asthma attacks.

[admiralrohan]

Why are you linking your app to anxiety and stress for V2? The earlier launch post had no mention of that.

[subharmonicon]

I recall the original post about Lungy.

Having had an incentive spirometer prescribed for post-surgical use after being on bypass, my experience was that it seemed boring and like a waste of time, so anything that makes breathing exercises more engaging and feel more worthwhile is a win.

[lukko]

Yes, exactly - that's what I saw working on post-op wards – the spirometer would just sort of sit on the bedside and collect dust.

[its-summertime]

What medical research is this based on? Isn't general breathing exercises, generally bunk?

edit: Having any medical-adjacent app collect any data for the use of advertising (according to the app page) seems really wrong.

[lukko]

Hey, breathing exercises do seem to have quite a positive effect, and are very low cost and low risk - recent meta-analysis here [0]. One of the reasons the evidence base is so patchy, is that compliance is generally quite low, which is one of the reasons for making a digital platform that can map any benefit to how frequently patients use the platform.

The wellness version only creates an anonymised token to track installs - no other data is shared. The medical device version will be a separate app.

[0] https://pubmed.ncbi.nlm.nih.gov/39477355/

[throaway920181]

Having done plenty of yoga in my life, I can tell you that breathing exercises are not "bunk."

[biglung420]

Me and my brethren have been using this tons :) I could most respectfully request a breathholding feature, hyping one up to hold ones breath for a minute and reminding to pass it left

[zackify]

How would you compare to a general meditation app like “Waking Up” curious if you’ve used it.

[lukko]

In general, Lungy is more an active form of meditation, so rather than closing your eyes and listening to guided instructions or following a timer, it relies on the combination of real-time feedback (showing your breathing with interactive visuals) and the physiological effects of changing your breath pattern for relaxation. So, you focus on what is going on in the moment, as a form of mindfulness.

It's less 'cognitive' than other apps, but a few studies have shown breathing exercises are as effective for stress as guided meditation, but also much simpler to follow [0]. I'm always slightly surprised at how effective breathing is in helping relaxation - although it obviously makes a lot of physiological sense. So, Lungy is designed to make a practice simple / fun to do each day.

[0] https://med.stanford.edu/news/insights/2023/02/cyclic-sighin...

[ChrisCinelli]

I remember this one: https://play.google.com/store/apps/details?id=com.hakjav.hel...

[hinkley]

When I was a boy they called that “biofeedback”. Damn kids ruin everything.

[lukko]

Hahaha - we are adding in HRV & heart rate tracking - then I think we can officially call it 'biofeedback' :)

[r0fl]

I tried this when it first came out but it always felt gimmicky and didn’t work randomly Will give it another try

Great idea and ux

[lukko]

Cool, thanks - its had quite a few updates since then. Will be interested to hear what you think.

[HumblyTossed]

What would be the advantages of this over, say, setting a timer and doing box breathing?

[amelius]

FDA approval pending?

[lukko]

yep - it would be MHRA (UK) initially

[bsaul]

Hey,i'm trying it and just a sidenote : the french translation is atrocious (to the point where you may completely misunderstand the feature). I had to translate back to english in my head to try and find the original meaning.

A quick example : "detection de l'haleine" instead of "detection du souffle".

"Haleine" in french is mostly used to mean the "smell" of the breath. And i found examples like this in almost every screen.

[lukko]

Oh, thank you for pointing that out!

If you notice any more typos / terrible translations please send to hello [at] lungy [dot] app and I'll get them fixed. Thank you!

[prox]

Thanks for the reminder, I used to use Lungy a lot. Forgot about it.

I just tried v1 again, it blocks me from using it because it wants the microphone but I don’t want to give access. Can you make it optional in settings? Just following the visual is enough for me.

Don’t think it needed it when I used it. Does v2 also have the same issue?

[lukko]

Yep - it's now fully optional, I think probably just delete the old version and go through onboarding again (and select No Mic Access). You'll then get a sort of simulated breathing response, rather than the actual input.

[mromanuk]

I'm working on a meditation app, using an llm as a guide. It tracks your heart rate using the main camera of the phone, later will add breathing. Soon to be released.