Health workers increasingly use mobile phones and tablets to provide services (often referred to as an ‘mHealth’ intervention). For instance, health workers use mobile phones to communicate with patients and with other health workers (one of several telemedicine strategies), keep track of medicines and supplies, notify births and deaths, search for information, and for decision support. Some mHealth strategies may be particularly relevant in situations and settings where it is difficult to meet patients, the public, and other healthcare staff face-to-face, such as during pandemics.