This chapter explores kindergarten children's use of specific online applications such as WhatsApp and YouTube to maintain social relationships between each other and with their classroom teachers during the COVID-19 pandemic lockdown. Using Vygotskian theorisation of learning through interaction with more expert people (teachers and parents) and Leontev's theory of functional organ, this study verifies that children often learned without an expert's presence, using strategies such as trial and error and discussion, and through maintaining social relationships among themselves and with their teachers. Specifically, the study involved two Italian kindergartens (42 children) and six teachers. Analysis of the children's work and of teacher interviews shows that, during the Italian lockdown, the pre-school children used applications as learning environments in the form of functional organs, and this proved useful for carrying on kindergarten activities and for maintaining social relationships.