This article argues that ‘beauty apps’ are transforming the arena of appearance politics and foregrounds a theoretical architecture for critically understanding them. Informed by a feminist-Foucaultian framework, it argues that beauty apps offer a technology of gender which brings together digital self-monitoring and postfeminist modalities of subjecthood to produce an hitherto unprecedented regulatory gaze upon women, which is marked by the intensification, extensification and psychologization of surveillance. The article is divided into four sections. First, it introduces the literature on digital self-tracking. Second, it sets out our understanding of neoliberalism and postfeminism. Third, it looks at beauty and surveillance, before offering, in the final section, a typology of appearance apps. This is followed by a discussion of the modes of address/authority deployed in these apps – especially what we call ‘surveillant sisterhood’ – and the kinds of entrepreneurial subjectivity they constitute. The article seeks to make a contribution to feminist surveillance studies and argues that much more detailed research is needed to critically examine beauty apps.