“…Smartphone devices are now widely used, with 64% of the US and 74% of the Australian population owning a device in 2015-16 [10,11], and 62% of smartphone owners reporting that they used their phone to access health-related information in the past year [10]. Like Internet-based interventions, smartphone apps offer numerous advantages in terms of addressing public health issues [12,13], such as increased accessibility, portability of information, lowcosts, anonymity, and the ability to provide tailored feedback and support.…”