A survey of more than 1,000 consumers from ON World showed that fitness is the most important application for wearable users. More than half of likely wearable device owners would use their devices, either activity tracking devices or smartwatches, for fitness.

The mobile sensing sports and fitness part of the connected mobile sensor market will have $10.5 billion in annual revenues this year -- three times what it made in 2014. By the end of 2019, ON World predicts, over 1 billion mobile sensing devices that support sports and fitness will have been shipped worldwide.

“Over $1 billion in venture funding, more than 600 products and expanding offerings from the mobile/IT industry promises to make 2015 the year of mobile sensing,” Mareca Hatler, ON World’s research director, said in statement. “With standards-based mobile sensing solutions becoming widespread due to the popularity of activity trackers and smartwatches, the market for mobile sensing devices supporting fitness apps will more than triple this year.”

Although smartwatches are enjoying some time in the spotlight, ON World's research shows consumers still have a healthy interest in dedicated fitness activity tracking devices: 39 percent of likely wearable consumers expressed an interest in such devices, a jump of 22 percent since ON World's 2014 survey. Two in five respondents said they would pay $99 or more for a wearable. And in 2014, activity tracking devices outsold smartwatches four to one.

Last year, more than 5 million smartwatches with support for sports and fitness apps shipped last year, and half of those were dedicated activity tracker-smartwatch hybrids, a category that includes products from sports suppliers like Garmin and Polar, tech companies like Samsung and Microsoft, and wearable activity tracker startups like Fitbit. But ON World predicts that in five years general purpose smartwatches with fitness apps, such as the Apple Watch, will make up more than 70 percent of the smartwatch market.