Smith writes, "The use of health apps has increased considerably in recent years. In 2018, there were 62.7 million monthly health app users in the United States. Just three years later, in 2021, that number jumped to 86.3 million monthly users. Likewise, the number of consumers willing to wear smart fitness technology has more than tripled in the last four years, from 9 percent to 33 percent of U.S. consumers."