CTApp: Teaching Students Computational Thinking Through a Mobile Application: https://ctapp.eu/ CTApp is a new mobile game in an escape room format. The aim of the player is to answer a series of questions and solve problems. The game combines the concepts of Computational Thinking and Serious Game. The game can be used by primary school students aged between 12 and 18 who speak English, Greek, Italian or Polish. Pupils will be able to use the solutions developed in the project in their school subjects.