Computational thinking (CT) and understanding how programs are executed are internationally acknowledged as necessary for today’s students and citizens of tomorrow. Despite the multifaceted nature of CT, the introduction of CT and associated concepts such as coding is regarded as developmentally acceptable for preschool and kindergarten children. Furthermore, there is a considerable influx of software offering various interfaces and styles which facilitate the introduction of children aged 4–6 years to essential CT, coding and problem-solving skills. However, the fast-paced developers produce apps, and the breadth of the available apps has gone beyond what is reasonable for researchers and experts in the domain to evaluate. This chapter presents a systematic literature review on the available software to encourage preschoolers’ introduction to CT and coding skills.