The adoption of technology in our daily activities increased the time that we spend in front of the screen and changed the way we communicate and work. In recent years, many big companies started to develop and implement screen time management tools in their products to educate the user on how to improve their digital health. Those tools are an important step in the process, they bring awareness and help the users to change their habits. Several studies have focused on screen time tracking apps but not from the design perspective. Therefore, this thesis aims to explore the design of screen time management apps by developing two prototypes, which were used to evaluate different design elements and features. The results of this thesis present a guideline on how to improve the design of the existing screen time tracking tools and what additional features could be added to fulfil their aim and encourage users to change their behaviour.