What

I wanted to develop a tool for both amateur CrossFit athletes and coaches for CrossFit Hakata gym, with a possibility to extend the app usage to other CrossFit gyms.

The app would allow:

• For coaches - create and manage class schedule; create and manage class content (workouts-of-day); athlete’s performance to adjust class programming.
• For athletes - save the results of workout-of-day; track their performance and progress; make (or cancel) a class reservation; share their score on a daily whiteboard and see the other athletes' score.

How

To implement this functionality, I decided to use:

• Dart/Flutter for mobile clients (Android, iOS).
• Kotlin, Ktor, and GraphQL to implement API.
• PostgreSQL as the database.
• Django framework and Vue.js for “administrator’s” site.
• Sentry for error monitoring.
• Docker, Docker Compose, and Docker machine for deployment.

Problems

I seriously underestimated the amount of work that is required to pull off this kind of project. As a result, due to lack of time to work on this project, I decided to reduce the application functionality to a minimal vital product (MVP) which then was released. The MVP allows users to track their one-rep-max (1RM) for different weight-lifting movements (single and complex); create new complex ones if needed; quickly get the value of 40-95% of 1RM.

After the release of MVP, I postponed the work on the project.

Results

• Android application released and available on Google Play (limited to Japan)
• iOS application released and available on App Store (limited to Japan)
• A landing page with application privacy policy and some related videos is created and deployed.
• I got experience in creating and releasing applications using Flutter.
• I contributed to the Flutter project.