Table 3.

Key themes and quotes arising from participant feedback after data collection.

Themes and summary of main views		Example extracts
Positive usability and engagement:
	Easy to use and visually pleasing Interest and perceived value of research topic Potential to inform and influence clinical care Enjoyed using the diary entry, or found useful Feedback graphs helpful Acceptable daily scoring entry Training and technical support helpful Passive monitoring acceptable	“I know myself the weather is a massive factor...Everybody I know has got a smartphone, so if it can improve people’s health and their condition and how they’re managed then brilliant.” [P13] “The way I look at it is it probably will help me in the future. But it'll help a lot more people with their symptoms and especially if it's going to go through to GPs and consultants.” [P4] “I’m really impressed with it...I think anybody could use it...even people that are not technically minded.” [P3] “Using the slider to score my symptoms was very easy and simple...I thought the motif was very well designed and very simple to use.” [P5] “I’m a bit of a nerd, so I will probably have a good look at those [graphs] to see how I have been scoring during the pilot.” [P11]
Barriers to ongoing engagement:
	Perceived lack in technical skills Training and support needs Battery life Problems with graphs and slider Phone not carried at all times Passive monitoring not accurate or too intrusive	“Accessing the app was difficult for me, because I’m not used to smartphones.” [P15] “It’s a hindrance in one sense, because the phone is totally alien, to me so when trying to update the app, I found myself struggling. As with everything, you would learn if you had it for any length of time.” [P19] “I ended up deleting the apps as they just drained my battery and I didn’t what to get caught out and not be contactable as my son is in and out of hospital.” [P6] “I tried to access the feedback graph area, and it just wouldn’t load it just keep saying, loading so I didn’t try again.” [P19] “I had a stroke then a fall and broke my hip I’ve been in and out of hospital and a care home so it was hard for me to carry on with it for the whole sixty days.” [P12]