Background Increased levels of wellbeing contribute to people being more productive, resilient, physically healthy and showing lower levels of mental illness. Using mobile apps to increase wellbeing in young people is becoming the method of choice. This study sought to critically appraise the current evidence base with regards to young people's (16–24 years of age) engagement with wellbeing apps. Methods A systematic review of the literature and narrative synthesis was conducted to investigate users’ characteristics and other potential engagement elements. A total of 11,245 titles, 160 abstracts and 68 full-text articles published between 2002 and 2021 were screened, of which 22 studies were included. Results Main themes/findings indicated that a user's engagement with wellbeing apps was dependant on the presence of strong identity elements, including motivation, mood and values; design elements such as meaningful rewards, short duration of studies and seamless automatic delivery with low contact with researchers; and being innovative and contextualised. The majority of the studies did not report outcomes by social determinants such as ethnicity, education and others. Conclusion This research reflects on the need to consider participants’ individuality when designing app mediated wellbeing interventions.