One of the major challenges in today's world is the problem of obesity in children and adolescents. According to the data from the World Health Organization, the number of obese children over 5 years old reached 124 million in 2016. With the youngest in mind, the FitKiDDO team decided to tackle this problem by creating the first training and dietary application for children and adolescents. Their goal is to educate and support this group in leading an active lifestyle through methodically planned trainings and dietary guidelines. The FiTKiDDO application is full of suggestions on training and nutrition, as well as an engaging graphic design which will appeal to every child.