Smartphones demonstrate growing popularity as a delivery mechanism for pediatric interventions for multiple reasons. First, smartphone ownership is growing exponentially in the United States (Pew Research Center, 2018) and internationally (Poushter, 2016). Many now rely on smartphones as their sole source of Internet access (Smith, 2015), particularly users who are younger, minorities, and of lower socioeconomic status (Pew Research Center, 2018). Smartphones therefore promote access to large numbers of diverse groups, and do not require users to have costly broadband and/or computer access nor to take the time to physically sit down in front of a computer to complete intervention tasks. Second, smartphones tend to be carried throughout the day, promoting in-the-moment and ongoing opportunities for assessment and intervention (Proudfoot, 2013). Smartphones therefore also represent a delivery mechanism that is already highly used in daily life, promoting the likelihood of higher intervention use, and potentially overcome barriers to traditional delivery mechanisms, such as forgetfulness (Mohr et al., 2010). However, while smartphones are growing in popularity as daily tools and as a delivery mechanism for evidence-based pediatric interventions (Fedele, Cushing, Fritz, Amaro, & Ortega, 2017), concerns are present in the mobile health (mHealth) literature around their efficacy for specific pediatric populations (Grist, Porter, & Stallard, 2017).