Digital technologies have become an integral part of the educational process, which has fundamentally changed the way we teach. Educational applications offer innovative approaches to learning and have the potential to significantly influence the development of students’ key competences. Many of them have become an important tool for self-study or online learning and now also for face-to-face learning, so they need to be given sufficient attention. This paper focuses on the current state of the use of applications in teaching at the lower secondary schools in the Czech Republic, their impact on the development of key competences and presents a possible categorization of educational applications with regard to their use. The research was conducted through a questionnaire survey among lower secondary school teachers across the Czech Republic. Based on the collected data, an analysis of the most well-known teaching applications for lower secondary schools was conducted. The results show that the frequency of use of apps in teaching exceeded 80% regardless of the length of experience of the teachers and the subject of teaching. The most frequently used applications include Kahoot, Google Classroom and Wordwall. Depending on the task, these applications can develop communicative, learning and problem-solving or digital competences.