Shaun Donnelly Grew Personal Best While Keeping a Job

Building Personal Best While Holding a Job

Shaun Donnelly adjusted the balance between his day job and his own business several times while growing Personal Best, a workout tracking app. He built on the side of a full-time job, then tested going full-time for a few months at a stretch, and after returning to employment he shifted to three days a week of contract work alongside running the product. His case shows the process of securing income to support his life while gradually increasing the time he could spend on his own product.

The starting point was at home in 2020. Donnelly, a web developer working at Skyscanner at the time, began learning iOS development in the evenings and on weekends as COVID-19 cut back going out. SwiftUI was an approachable tool for someone comfortable with React, and because he enjoyed exercise he picked an app that would draw on data from Apple Health. The choice also carried the calculation of not having to take on server development and support for several operating systems at once.

What Personal Best works with is the workout history already stored on the user's device. It pulls in data saved in Apple Health and presents per-workout statistics, record rankings, and changes over time in an easy-to-read form. If an existing workout app writes its records to Apple Health, that data can be used, so users can keep their familiar recording habits and add analysis on top. The business opportunity lay in the experience of reading back and comparing the collected data.

Donnelly released Personal Best on the App Store on May 2, 2020. But downloads from May to September, when he relied on word of mouth without any marketing, came to a little over 200. In June he added Personal Best Pro, a one-time purchase that unlocked extra features, and around the end of the year it had reached about 300 purchases. Paying customers did appear, but he stated clearly that he had no plans to quit his job at the time.

The breakthrough for the first wave of users was the release of iOS 14. He prepared widgets and workout route maps for the new operating system, and notified journalists who were looking for related apps about the update. When Personal Best was included in articles on 9to5Mac and TechCrunch, downloads on September 17, 2020 reached 951 in a single day. Once the interest that lasted a few weeks subsided, it fell back to 5 to 10 downloads a day, but he learned how to promote a product in step with a platform's update schedule.

In 2021 he also tested the effect of free distribution. Unlocking the paid feature for a day and being featured on Apps Gone Free brought a big jump in downloads, but annual revenue came to about $1,500, slightly down from about $1,700 the year before. Donnelly explained that many users delete an app soon after getting it just because it is free. It was an experience that made it hard to judge business growth from a surge in installs alone.

Reshaping the Job and the Revenue Model

That July he left Skyscanner and joined Duffel, a travel technology startup. He was happy with the new job, but the pace was intense, and by the end of a day he was drained enough to want to step away from the computer and rest. As a result, the pace of Personal Best development slowed sharply in the second half of the year. Even with living costs stable, he had to manage separately the energy and focus needed to keep developing.

At the end of 2022 he talked with his company and changed his own role first. He stepped down from engineering manager work and went back to being a software engineer. He found helping colleagues grow rewarding too, but he judged that he was happier when concentrating on technical problems.

He changed his work schedule as well. He kept the 40-hour week but applied a compressed schedule, working 10 hours a day from Tuesday to Friday. The Mondays this freed up let him handle personal matters or develop his app. It was a way of creating a continuous block of working time in agreement with his employer, and he recorded that his mental room and productivity improved from the start of the arrangement.

He reworked the revenue model that summer as well. It had been structured so that paying $5 once unlocked the Pro features, but to build a stable second income he introduced monthly and annual subscriptions and offered a lifetime pass alongside them. Existing Pro buyers were granted lifetime access, preserving what they had already paid for.

Right after the change, the scale was still small. At the end of 2022 recurring revenue annualized came to about $250, and his goal for the following year was to double it to $500. At this point subscriptions were far from covering living costs, but for Donnelly they were a sign that there were customers paying regularly to keep using the product.

Going Full-Time and an App Store Feature

In June 2023, as the company moved to cut staff, a bigger option opened up. Donnelly applied for a voluntary redundancy and decided to spend several months entirely on Personal Best instead of looking for the next job right away. Because app income made full-time living hard to sustain at the time, he planned to set aside a modest severance payment to fund an experimental period. He also stated the condition that he would look for full-time work again if he needed money.

During the full-time period he focused on the core screens users come into contact with directly. He rebuilt the sharing screen that turns a workout record into an image, and rewrote the Apple Watch app to match the new operating system's design. While improving the workout list and summary screens, he brought photos and route maps to the fore, and he also reworked the payment screen. He was able to push through all at once the improvements he had put off because it was hard to find the time before.

He reconsidered pricing too. After comparing with similar apps, he judged that his own price was too low and raised it, and in his observation purchases did not fall. He set existing subscribers to keep the previous price. He ran the experiment of raising prices and the work of managing the burden on existing customers together.

The biggest change in traffic came when the app was included in a featured list on the US App Store. One day the active trial subscriptions he saw in RevenueCat had grown to roughly ten times the usual level, and only the next day did he learn about the feature. Donnelly said daily active users also jumped from about 1,000 to around twenty times that. Along with product improvements and the price adjustment, growth accelerated as new users got a chance to discover the app.

In the 2023 results, Personal Best's annual downloads were about 87,000 and revenue was $18,200. Monthly recurring revenue at year's end was $1,279, surpassing the $1,000-a-month goal he had set midway through the year. Donnelly named roughly five months of full-time development and the App Store feature as the two turning points for growth. It was the year an app that had stayed small for several years began to increase revenue in earnest.

Growing the App Again After Returning to Work

After finishing the full-time experiment, he went back to work. The job he started in December 2023 did not suit him well, and in 2024 he moved to a company he was happier with. While continuing to run the app, he kept making choices to improve the working conditions of his main job.

The app kept growing in the meantime. In 2024 it was named App of the Day in the App Store in more than 150 regions, and annual downloads were about 180,000 with revenue of roughly $35,000. Revenue that had nearly doubled from the year before increased his income outside of work. At the same time, since featured placement was a major traffic channel, Apple's editorial choices had a large impact on the business.

There was also an attempt to spread income across several apps. He released SalaryPig and two quiz apps, but in 2024 the combined revenue of the four apps other than Personal Best came to only $713. He had planned to scale the quiz apps quickly using shared code, but he stopped making more because of the burden of the app review process. Seeing this result, he decided to focus on Personal Best in 2025.

He also allocated time to maintaining a grown app on his own. In 2024 he rebuilt the record ranking feature, whose old data design was blocking improvements, and moved the FAQ that had been on the website into the app. Because inquiries kept arriving about answers already in the documentation, he changed where users find the answers. To protect his limited development time, he had to deal with maintenance and customer support alongside adding features.

Finer Experiments and the 2025 Results

In March 2025 the startup he was working at suddenly closed. Donnelly again devoted himself to Personal Best for about six months, and from September he began three days a week of contract development work. It was a working arrangement that secured income from outside work while allocating the rest of his time to his own app.

His experiments in growing the product became more fine-grained as well. In April 2025, to compare two payment screens, he implemented an A/B test that showed a different version to each user and recorded the response. Using his existing analytics tool TelemetryDeck integrated with RevenueCat, he linked screen impressions to purchases. Beyond evaluating how polished a screen was, he began checking which configuration actually led to payment.

In pricing experiments he also reflected local purchasing power. He cut subscription prices in India by about 90%, and disclosed that 2025 revenue in India rose 128% from the year before. Donnelly interpreted it as more buyers at the lower price offsetting the drop in unit price. It was a case showing that the same pricing strategy need not apply to every country.

In the 2025 results, downloads and revenue moved in different directions. Personal Best's annual downloads fell from 180,000 to 137,000, but the annual revenue of the app business he disclosed rose to about $45,000. As of December 31, 2025, monthly recurring revenue was $3,630. He earned more revenue from fewer new downloads, and Donnelly assessed that his monetization improvements were having an effect.

What can be read from this case is that there are many stages even in how someone runs a job and a business together. A person can adjust their role and working days to match their own energy, test full-time work for a set period, and take on outside work again if needed. The important criteria are the product's actual revenue and the time a person can keep putting in. Donnelly's path shows how it is possible to change the way one works little by little while checking those two conditions.