A training app built around streaks people actually keep.
Pulseline
Pulseline is a founder-led fitness brand with a cult following around a progressive-overload training method. The founder coached 60 clients over video calls and had a waitlist she couldn't serve. The product thesis: the method works because of accountability, not content volume.
Fitness apps live or die on week-four retention, and the category averages under 10%. A content-library app would have commoditized the method. The app had to reproduce the feeling of a coach noticing your work — without the founder personally watching 10,000 users.
Retention designed before screens
We started with the notification and streak model, not the UI. Sessions log in under 20 seconds, streaks tolerate a missed day (rigid streaks kill comebacks), and the weekly recap reads like a coach's note, generated from actual training data.
A tappable prototype in week one
Twelve waitlist members used a Figma prototype for two weeks. Their confusion reshaped the session logger twice before a line of Swift was written — the cheapest redesigns we ever shipped.
Native on both platforms
Timer precision, HealthKit and Health Connect integration, and offline gym use pushed us native — Swift and Kotlin with a shared design system and a thin sync API.
The 20-second session log
Logging a set is three taps with smart defaults from last session. Progressive overload suggestions appear inline — the method is embedded in the interaction, not explained in videos.
Recaps that feel coached
Sunday recaps summarize volume, progression, and streak health in the founder's voice, assembled from telemetry. Users screenshot and share them — the app's cheapest acquisition channel.
downloads in first six months
day-30 retention (category avg. ~9%)
App Store rating across 310 reviews
monthly recurring revenue at month six
“I was terrified an app would flatten what makes my coaching work. Instead they built the noticing into the product. My retention numbers embarrass the category.”
Maya Okafor
Founder, Pulseline