Deep Core — iOS App

Deep Core is a guided breathing app for the deep stabiliser muscles around the spine — the transverse abdominis, pelvic floor, multifidus and diaphragm — which are activated by a forceful exhale rather than by crunches. Five exercises, five minutes, hands-free and free on the App Store.

This is my first iOS app and the first product I have designed, built and marketed end to end. My partner Michele designed the brand, the illustrations, every screen and Beanie — the small orange bean who lives on the home screen. I owned the architecture, the code, the infrastructure and the release.

Built in Swift and SwiftUI with xcodegen so the project file stops being a merge-conflict machine. Purchases run through RevenueCat, analytics through EU-hosted PostHog behind a first-party proxy, and the paid surfaces shipped dark behind feature flags so switching on monetisation was a config change rather than a resubmission. Persistence is UserDefaults plus iCloud key-value store — no backend, so it survives reinstall without a server bill.

The marketing was a build problem in its own right: an Astro site deployed to S3 and CloudFront on a git tag, a Buttondown waitlist, and video ads voiced with ElevenLabs using the same voice the app uses for coaching, so an ad and the product sound like the same thing.

Result: live on the App Store, running on about €30 a month, with four App Store rejections along the way that taught me more about shipping than the code did.