The smartphone has become ubiquity in everyday life. Today, it is no longer the question of what these devices are capable of, but rather on related effects of using it. During recent years, studies increasingly focused on smartphone-related effects on cognitive functions, however, existing findings are limited. Therefore, the present manuscript aims to provide an overview of previous findings but also to highlight existing gaps in the field of smartphone-related effects on attention, inhibition, and working memory. We provide a hypothetical model assuming a differentiation between immediate and long-term effects of smartphone use on respective cognitive functions. It also describes the relations between attention, working memory, and inhibition, which have been extensively studied in the past. The model further suggests a quantification of smartphone usage based on different quantitative parameters, such as usage time, usage frequency, used applications, and received notifications. In addition, individual attributes and situational factors are highlighted as directly influencing attention, inhibition, and working memory, but also moderating smartphone-related effects on respective cognitive functions. Until now, there are many unresolved questions regarding the effects of smartphone usage on specific cognitive functions. However, until these are clarified, and despite a growing literature on adverse effects, it should be kept in mind that a general smartphone use may also have beneficial effects on certain processes of attention, inhibition, and working memory.