Shaun Donnelly is an indie iOS developer in London who builds Personal Best, a workout tracker for iPhone, iPad, and Apple Watch. It reads the workout data already sitting in Apple Health and turns it into stats, animated replays, goals, leaderboards, and editorial-style images people can share. The pitch is simple: if your runs, rides, or gym sessions already write to Apple Health from apps like Strava, Peloton, or Nike Run Club, Personal Best makes sense of all of it without any extra setup.

He started the app around 2020 as a small side project and kept building because he enjoyed it. By the end of 2025 it had passed 500,000 lifetime downloads and was being shown by Apple as an example of good practice at developer events. The app is free to download, with a subscription that he added in 2022 to start earning recurring revenue from the people who use it most.

In his public 2025 review, Shaun shared the numbers from RevenueCat directly. Monthly recurring revenue finished the year at $3,630, up 31% from $2,769 on the same date a year earlier. Total sales for 2025 came in at $45,000 versus $35,000 in 2024, a 29% rise. The interesting part is that this growth happened while downloads actually fell, from 180,000 in 2024 to 137,000 in 2025, with monthly active users holding steady at around 42,000. More money from fewer new installs suggests his work on pricing, retention, and converting active users into subscribers is paying off.

Most of the growth came from inside the App Store rather than outside marketing. Apple features, organic search, and steady app store optimisation work (testing keywords and screenshots) did the heavy lifting, supported by posting on the app's Instagram and TikTok accounts. Shaun also spent 2025 finishing a long database migration to Swift Data, improving accessibility, and shipping quality-of-life features like manual workouts, custom dashboards, and better filtering.

For 2026 he set a deliberately tough target: reach $5,000 MRR, which would mean growing recurring revenue by another 38%. His other goal is more qualitative, getting Personal Best to a point where it feels like a finished, cohesive product with an obvious benefit for anyone who works out.