Table 2.

Feedback on the mISkin app provided by participants and changes introduced.

Intervention component	Category of suggested changes	Sample quotes	Changes implemented in the intervention
Skin assessment	Order of questions	“Information about specific skin types was quite useful.” “Having the question about the skin reaction before the color of the skin in the skin assessment.”	The question order about skin reaction was changed.
Videos	Video content	“It would be quite useful to see the clip again after seeing all the information in the little quiz or having the video after.” “I like the practical advice about how much sunscreen to put on. I would say it would be more effective if it didn’t leap straight into skin cancer and it started with choose a good sunscreen and then link to the consequences of not doing it.” “I think it would be quite good to have a checklist at some point that we could look up.”	A video menu was added to make navigation through different sections easier (eg, how to apply sunscreen and instructions for other sun-protection behaviors)
	Video length	“Instead of having a very long video having the different sections.”	Different snapshots of the videos were added to the menus, reducing the information displayed. The video menu was organized so that skin cancer information is the last video displayed.
Sun safety quiz	Content	“In the quiz, instead of saying just true or false, say something like you’re correct or that’s wrong.” “I like the quiz bit; you can do it once.”	Explicit feedback on performance was added.
	Confusing statements in quiz questions	“Tricky question the one about sunburn doubles the risk of skin cancer.”	The sentence was changed to “increased risk of melanoma.”
Prompts	Content	“Like you say stay out of the sun between 10 and 4pm. Give some ideas how to do that. Like say have a nice long leisurely lunch sounds much better than you must stay in the shade between 10 and 4pm.”	Some suggestions on how to seek shade between 10 AM and 4 PM were added to the reminders.
	Frequency	“I quite like it particularly the prompts. I would probably like to have a bit more, have the opportunity to remind me a bit further.” “I like the idea of a sunscreen reminder app that I could set up to my preference.”	A preference setting was added to the alert service, so that reminders are customizable (ie, 30 minutes to 2 hours).
UVa photographs	Reaction	“It’s quite scary though, is it? I’ve seen a few of these before and it always makes you feel I should put more on.” “It’s a good idea to have it in and it’s better than when that woman talking. Just put it a bit earlier in the app. it’s the shock factor that would make you think: oh I don’t want to look like this. So I suppose it should be in...” “It’s quite scary; it might put me off the app. that the last thing I want to see on holiday.”	UV photographs were moved to the video menu (participants visualization of these depends on their choice) and were placed as the last available option to be seen. A brief explanation about the meaning of the UV photographs was also added so that participants are aware of what it implies and know what to expect.

^aUV: Ultraviolet.