https://shiihaa.app/ Writing from the shii·haa team on real-time breath detection, biofeedback, on-device ML, and the clinical thinking behind the app. Built by a physician. en © 2026 Felix Zeller felix@shiihaa.app (Felix Zeller) felix@shiihaa.app (Felix Zeller) Tue, 21 Apr 2026 18:45:00 +0000 shii·haa static builder https://shiihaa.app/blog/teaching-app-to-hear https://shiihaa.app/blog/teaching-app-to-hear Tue, 21 Apr 2026 08:00:00 +0000 felix@shiihaa.app (Felix Zeller) Engineering Lessons from shipping real-time breath-phase detection on mobile audio — three engineering failures, their fixes, and where machine learning honestly fits. Plus the two-stage research framing: validate the deterministic detector first, then use its qualified labels to train personalized ML. https://shiihaa.app/#blog-biofeedback https://shiihaa.app/blog/beyond-the-timer Tue, 01 Apr 2026 08:00:00 +0000 felix@shiihaa.app (Felix Zeller) Insights Why your heart rate tells you more about your breathing than your lungs do — and what shii·haa's biofeedback actually measures that generic timer apps can't. https://shiihaa.app/#blog-audio https://shiihaa.app/blog/ios-audio-analysis Thu, 03 Apr 2026 08:00:00 +0000 felix@shiihaa.app (Felix Zeller) Engineering The technical story behind our open-source Capacitor plugin — and why Apple's WebView broke our microphone. Now on npm as @shiihaa/capacitor-audio-analysis, MIT-licensed.