This paper contributes to the literature on the phenomenon termed mHealth through a critical examination of wearable posture-tracking technologies. The paper specifically reports on a qualitative document analysis of promotional materials for three devices, carried out with the aim of assessing their mode of operation, the logic underpinning their development and their purported benefits for users. Findings initially highlight how Lumo Lift and Lumo Back, made by the company Lumo Bodytech Inc., and Prana, made by Prana Tech LLC, are designed to enable haptic surveillance and discipline whereby the body is monitored and ‘reprimanded’ through the touch. These forms of interactive posture training are underpinned by scientific insight from fields such as biomechanics and by data science on consumer posture habits. In turn, the benefits for those engaging with commercial posture-tracking devices are said to include, unsurprisingly, better posture, but also a less tangible form of ‘optimised’ living. With these findings in mind, it is argued that the arrival of interactive posture technologies has two main implications. In one sense, whereas good posture has historically been imagined as a dividing line between ‘civilized’ humans and ‘uncivilized’ others, devices such as Lumo Lift make posture into a matter of posthuman optimisation: humans and non-humans are enfolded in the pursuit of self-betterment. In another sense, posture technologies are important in emboldening the wider mHealth phenomenon, privileging as they do the idea that commercial technologies are now allies and not foes when it comes to improving health.