With their widespread use in the Global South, mobile phones are attracting growing interest from international aid actors and local authorities alike, who are positioning mobile technology as a growth driver and a solution to many social problems. Initiated by giants of the digital industry, these policies are reviving old questions about technological development, the relationship between the market sector and States, and the role of technology in the inequalities between the Global North and Global South. Through a multi-sited ethnography on maternal care in Ghana and India, this Element provides a first-hand look at initiatives that promise to improve poor women's health in the Global South through the use of mobile phones; a field known as Mobile Health or mHealth. Attentive to the way in which these technical objects modify power relations at both international and local levels, this Element also discusses how mHealth transforms care practices and healthcare.