The recent inclusion of computational skills in core curriculum by governments in the UK and Australia, has been linked to industry calls for schools to better equip young people with capabilities and dispositions aligned with needs of future high-tech industries and rapidly changing workplaces. This move has stimulated much interest in New Zealand, and while lacking any compulsory curriculum mandate, many teachers in K-12 classrooms are exploring the potential of coding tasks for developing computational skills as part of their mathematics, science and technology curricula. This paper reports findings from a study that used a unique data capture app embedded in iPads to record 9&10 year old students while they used two apps of very different designs for coding tasks. Using Studiocode video analysis software, data were analysed using a framework developed from Brennan and Resnick’s [1] three dimensions of computational thinking, to learn more about how these apps constituted useful environments for developing computational thinking. Results suggest that coding apps of a ‘teaching’ design complement apps where computational concepts and practices are applied to project creation, and indeed may be more efficient if the desired outcome specifically targets the learning of concepts. Implications for teachers exploring coding apps for computational thinking development are drawn.