Table 2.

Smartphone use: health behavior change technology.

Health behavior change devices and apps			Quotes
Use of wearable devices			“I have the Apple watch that I use for running too. And the Fitbit.”; “I have an Apple watch but I hardly ever go running.”; “[I use] a watch...to track my steps.”
Use of activity tracking apps			“I used to use the health app that [iPhone] comes with...See how much I’ve walked and stuff.”; “It’s called Lifesum...it tracks your calories for the day...I’ve seen some other people using and I was like, ‘that’s pretty cool.’”
Reason to use health apps or devices
	Positive feedback	“All of those big numbers.”
	Physical training	“Like [if] I’m going to train...”; “[Using a wearable device] depends if I’m doing a sport.”
	Interface	“I just liked the way it looked, the layout...when you go on there, they ask you a whole bunch of questions. And then they give you a certain amount of calories for your weight and your height and like your age. And then you put in what you eat throughout the day...And then it’s like a rainbow at the top. And it’s like a sunset at the top and then water—I don't know. it’s just a cool setup, I guess.”
Reasons not to use health apps or devices
	Pressure to workout	“Because it’s too much exercise...because I would want to get big numbers.”
	Uncool	“It’s sort of just inherently uncool to me.”
	Fear of losing device	“I feel like I’d lose it.”
Discontinuation
	Inconvenient/no new insight	“[Sleep app] I don’t like to have my phone by my bed because it lights up and stuff. It had to be like pretty close to you for it to track...I mean like it was [useful]. It told me if I was sleeping good or not. But I’m also a really good sleeper so it always was like deep sleep and I’m like okay.”
	Not necessary	“I just didn’t feel the need to have it. It was something to do.”
	Lost interest	“Well, at first, I would read them because it would just pop up, but then after like I would read them and they would just keep popping up and I wouldn’t care and I would just swipe up. So, I was like oh I didn't even read them. So, I deleted it.”
Perceptions of those who use cannabis			“Fitbit is like a preppy thing. It’s the kids that would be willingly spend $100 for something a phone app can do.”; “I’m just like oh my God, what a nerd. I just do not want to be associated with someone who is like, ‘Oh, I’ve got to get my steps in today.’”; “It’s a little obsessive to me.”; “At least they’re motivated.”