Nowadays students are surrounded by plenty of information resources and they use these multimedia streams parallel. This multitask working environment appears during lessons as well. This hyper attention symptom blocks students in the effective participating of the common work. Therefore more and more ICT tools appear and are used in schools from elementary schools to higher education. One of these possibilities is CRS (Classroom Response System) of which benefits are undoubted. Their usage makes lessons more diversified, more motivating for students who are used to and prefer to use applications and smart devices, more interactive. However we must not forget about the disadvantages either so in this paper we should like to give a look around this topic, present our own newly developed CRS system and speak about how we can use it in teachers training.