Growing an app from 100 to 70K active users
Dietitian Chris Cheyette and photographer Yello Balolia produced a visual guide for people living with diabetes. Here’s how we helped them successfully transition from books to apps.
Client Q&A with Chris Cheyette
What was the problem or opportunity that led you to developing an app?
We started the app soon after publishing our first book. We saw an opportunity to digitise our content and make it easier for users to search for foods and learn to count carbs.
How did the app change your business?
We could include a much larger food database and present more detailed nutritional information to users. We quickly noticed that parents and healthcare professionals were encouraging kids to use our app. This helped us engage a new audience.
What brought you to your partnership with Pocketworks?
A friend of ours built the first iPhone app and, over a period of a few years, we worked with several app development companies. It often felt difficult and we faced numerous issues. The final straw was when a supplier went into liquidation and we lost access to our source code.
In your search for the right partner, what were you looking for?
In our experience, the entire app development process was challenging. The main issue was the lack of a true partnership — we were simply commissioning work. Ultimately, we needed stability. That’s when we started discussions with Pocketworks.
If you were to start the app development process again, what would you do differently?
We would focus on partnership from the beginning. A long-term collaboration reduces risk and ensures a more stable development process. We’ve learned that it’s important to delegate more control to experienced developers rather than trying to micro-manage everything ourselves.
The award-winning carb-counting method
The Carbs & Cals App Journey
From niche books to digital platforms: The evolution of Carbs & Cals
From static to digital
"We started the app soon after publishing our first book, around 12 years ago. At that time, apps were just starting to gain traction. We saw an opportunity to digitise our content and make it easier for users to search for foods."
Expanding the food database and enhancing user experience
“Having an app allowed us to include a much larger food database and present more detailed nutritional information. One of the goals of the app was to make carb counting more accessible, especially for younger users.
Another key factor was flexibility — books are static, but the app allowed us to make updates, improvements, and learn from user feedback.”
The struggles in choosing the right partner
“The main issue we faced when trying to find a digital partner was the lack of a true partnership — we were simply commissioning work, which led to constant additional charges, poor communication and a less-than-ideal user experience."
Where Pocketworks stepped in
“Once Tobin stepped in, things improved significantly. We then transitioned to a partnership model with profit sharing. This approach reduced our financial risk and aligned both parties’ on the long-term goals for the app.”
Key goals and outcomes for the Carbs & Cals app
“Our main goals included:
- Stabilising the app and reducing bugs.
- Implementing better analytics to understand user behavior.
- Expanding the food database and adding features like a barcode scanner.
- Transitioning to a sustainable revenue model.
- Improving user reviews and App Store ratings.
All of these objectives have been met over time, and the app is in a much stronger position today.”
Carbs & Cals today
“The app currently has a database of over 200,000 UK food and drink items and we have a living, breathing app roadmap to keep updating and improving things.
Carbs & Cals continues to grow, has won numerous awards, and has built a UK user base of more than 70,000 active users.
The app and books have become a popular resource in the diabetes community and amongst NHS and healthcare professionals."
Key facts & figures
01
Rebuilt app and web platform from the ground up
Choosing cross-platform technology like Flutter allowed the team to develop more efficiently and update the app for both Android and iOS at the same time. The app also got a custom CMS to manage a vast database of over 200,000 food items.
02
Helps over 70,000 monthly active users
Since the new app was launched in July 2022, we've helped Carbs & Cals grow to more than 70,000 monthly active users.
03
Over 30,000 app subscribers
We've grown the subscriber base to over 30,000 users, with strong renewal and user retention rates. The app is a top performer against all subscription app category benchmarks.
04
900% revenue increase over two years
We've helped Carbs & Cals to grow their revenue by over 900%, generating funds to reinvest in further research and development.
Take a look at the behind the scenes
Annual mobile strategy workshop
Every app needs an aspirational goal and a strategy to get there. We spend a few days reviewing this each year as a team and setting the strategic direction for the year ahead.
Quarterly roadmap management
There's always so much to do, so we pick items that fit our strategy and try to blend bug fixes and quick wins, with bigger features.
User interviews & surveys
The team run continous user research around the roadmap. This helps us design for the people that will use the app and make key decisions about which features to focus on next.
App UI/UX design
The voice of customer informs how we design our features. We do fairly light design leading into development, and tweak and tidy up as we go.
Flutter app development, Cloud web portal & API development
Carbs & Cals is a Flutter app. This prevents us having to duplicate work on two platforms, allowing us to get features out to customers faster. Carbs & Cals is backed by a custom CMS that helps the team manage the data.
Product analytics
We're in the "measure what you need" camp and the apps have well thought out analytics that help us understand enough to make good roadmap decisions. We pay attention to key benchmarks, such as; paywall conversion rates, 7-day retention, 30-day retention, subscription churn and feature usage.
App store optimisation and growth marketing
Our app store presence performs well, and we're constantly experimenting and tweaking to try and improve our app visibility and user acquisition.
Alongside feature development, we're always running growth experiments to improve our conversion rates. This also includes experiments to help users succeed and be able to complete the jobs they're trying to get done in the app.
We run paid and organic activities focused on acquisition, retention, engagement and win-back to continually grow and maintain our user base.
“Given Pocketworks’ experience, fitness tracking, health monitoring and other digital health solutions could leverage their skills in creating impactful, user-friendly apps.”
Chris Cheyette
Diabetes Specialist Dietitian and Carbs & Cals co-founder
2025 Pocketworks Mobile Ltd