How We Built a Panic and Anxiety App: Püfür

A screen meant for a panic attack

The most important part of the app is the Panic button on the home screen. During a panic attack your hands shake, reading is hard and small buttons get missed. So we kept the buttons in the flow large and made sure they always stay in the same place: even when the card changes, the "Continue" button does not move, so the same spot can be tapped again and again.

The sentences on the cards are short and calm. They can be read aloud with the phone's own Turkish voice and can advance on their own. At the top of the screen our mascot Bulut keeps the breathing rhythm by growing for 4 seconds and shrinking for 6. A link to the emergency number 112 and a one-tap call to a trusted person added earlier are always visible.

Starting without searching for the app

In a panic attack even finding the app on the phone can feel hard. So we built a Panic widget that can be placed on the Android home screen. Tapping it opens the app straight into the panic flow, even if another screen was left open. Since finding a widget in the list is not easy on every phone, we added a "Panic button on the home screen" item in Settings; the phone itself asks whether to add it.

Why Flutter?

We wrote Püfür in Flutter: one codebase gives both an Android and an iPhone version. For phone-specific jobs like sound, notifications and the widget we added small native pieces. For example, we noticed that sleep sounds left a short gap when they looped back to the start; we removed that gap by writing our own player that chains two players one after the other.

The app has breathing exercises, lessons that explain anxiety, a mood journal, an anxiety scale, voice-guided visualisations, sleep sounds and calm games. They all share one design language: flat colours, soft illustrations and Bulut in every section.

Working without an account, protecting health data

Journal entries and moods count as health information. So the app works without an account and without internet; records stay on the phone. Anyone who wants can back up their records to the cloud with a free account. The backup is kept on servers in Europe, each user can only reach their own records, and backing up starts only with the explicit consent given when the account is created.

Anyone who wants to delete their account can do it inside the app; for someone who has already removed the app, there is an account deletion page on our website. Google Play asks for this too.

Testing every screen on a real phone

We check every new feature with automated tests; Püfür ships with 387 of them today. But some bugs only show up on a real phone. Before release we went through every section on a phone from start to finish: offline, online, creating and deleting an account, removing and reinstalling the app and restoring the backup.

These runs turned up a few bugs. For example, when a backup was restored from the sign-in screen, the screen went black while the app returned home; the cause was a page that was already closing being closed once more. We reproduced each bug with a test that catches it first, then fixed it, so the same bug cannot quietly come back.

Publishing a health app on Google Play

One of the most important things we learned was on the store side. Google Play accepts health apps, including mental health apps, only from organization developer accounts; a health app published from a personal account can be rejected. An organization account in turn needs company details and a D-U-N-S number.

If you are planning a health-related app, planning this step at the very beginning keeps a finished app from waiting at the store door. The wording in the app needs care too: Püfür is a support tool, it does not diagnose and does not replace treatment; we say this clearly both in the app and on the store page.

What's next?

Püfür will be on Google Play soon. If you want to bring an app idea of your own to life, you can write to us; mobile app work starts from $360 with us.