Computational Thinking is the new literacy. As technology continues to grow in importance in our daily lives Computational Thinking has become very important in our society and an increasing number of jobs require Computational Thinking skills. "CTApp: Teaching Students Computational Thinking Through a Mobile Application" Erasmus+ School Education project (2020-1-PL01-KA201-081924) main goal was to offer a fun game-based learning tool that teaches Computational Thinking and encourages interest in STEM. Advancing in levels also contained interactive content (such as interactive videos and quizzes). During the project, a lot of students benefited from being involved in the development and testing process because they saw a remarkable increase in their computational thinking skills and their understanding of computational logic.Recognized as a fundamental competency alongside reading, writing, and mathematics, CT involves analytical and algorithmic thinking to solve problems. In this paper we present the design, development and evaluation of the Serious Game, CTApp, that has been created to enhace students computational thinking skills in a playful way. A survey response group of 40 students provided initial usability feedback on the game. According to their feedback the game was really enjoyable. Findings from the evaluation were highly positive, indicating that the game provided both educational value and an engaging learning experience. Students showed improvements in the following areas:
(a) Computational Thinking Literacy &
(b) Motivation to learn.

Keywords: Distance Learning, Serious Games, Mobile Learning, Computational Thinking.