Fitness application to extend
elderly people’s active life

Platform: iOS, Android, Web

Technologies: Kotlin, Swift, ReactJS, ExpressJS, PostgreSQL, Nginx, AWS

Field: Fitness, health, longevity

Country: China


The application was designed for a Chinese startup. Its main idea is to maintain health and extend active life of elderly people..
Project origin: China, Hong Kong.
Balancd helps people over 50-60 years of age to exercise flexibility and balance to reduce the risk of falling.

The application owner Sarah Chung developed her own methodology based on the elements of Tai Chi gymnastics when she helped her mother cope with health problems. Sarah decided that she could help much more people. She was a personal trainer, but she believed that it was possible to exercise without a trainer’s presence, remotely, at home, using the app. So she asked Citronium to develop it.



To organize distance training, the application contains an individual training program, video lessons and fitness tests to track the progress.

Using the app, you can:

  • - select a training program;
  • - get reminded of the training;
  • - take a test;
  • - share the results on Facebook;
  • - use Facebook webview.


The system consists of two native applications (iOS and Android) and a web version for the administrator to manage exercises, training courses and get statistics on users’ progress.

User Story

1 The user fills in his/her personal data (gender, age, location, lifestyle and number of training sessions per week).

2 Then the user takes special tests for the application to choose the best training system. There are two kinds of training: Shaolin and Badiyanjin. They have different levels of difficulty. For convenience, video lessons with exercises are accompanied by texts.

3 After each training, users can assess how difficult it was for them in the feedback area.

4 They can also view statistics and share their progress on Facebook. It is possible to chat in a social network group right in the Balancd application interface.


The project was implemented by a seven-men team: a project manager, a designer,a quality engineer and four developers (Android, iOS, frontend and backend).
The Android-version is written in Kotlin. In spring 2019 Google declared this programming language one of the highest priorities for Android.
Another peculiarity of the project was the fact that the developers had to change standard approaches and add an additional button to the application. It was necessary because the application users are elderly people and they need such a button for the app to be understandable. The key points for the app were convenience and ease of use.


  • - The algorithm for training assignment is quite complicated, as there is a well-defined scheme for giving exercises by difficulty levels based on users’ tests and their feedback after the exercises.
  • - The team also gained experience in app localization in Chinese. To be more precise, it was the Cantonese dialect that we had never heard about before.


After the application was developed and gained popularity in Hong Kong, the idea of remedial gymnastics became of interest to social organizations. Sarah was also invited to the Shaolin Europe Association to present the project. Before the release, the application was tested by pilot groups in Spain, Norway and of course China. Now elderly people can do gymnastics to extend the active phase of their lives with the Balancd app in any place of the world.


Сара Чунг

Sarah Chang,
author of the unique methodology, Balancd application owner.

Citronium organizes the work so that interaction with all stakeholders is clear and fast. Well organized processes let them be fully absorbed in the development, but at the same time to answer questions fast and clear, especially when technical advice is needed. Citronium employs highly qualified specialists pleasant to deal with.
In any project people need time to get on with each other, but our teams quickly fit in and got involved. Dedicated project managers did a great job and managed to think through all the details and get useful feedback from users. It's great that the Citronium team quickly find and fix all the shortcomings. When necessary, they give recommendations on the product and offer creative solutions.