Table 1.

Post-pilot study interview themes, categories, and codes.

Theme and category		Codes
Acceptability of the intervention
	General impressions	Enjoyed use
	Usability	Easy to use Easy to understand Quick to complete
	Specifically endorsed app elements	Pain management advice Design and gamification mechanics Real-time any-environment reporting
	Challenges	Number of assessment questions Notifications Other technical problems
Potential active ingredients of the intervention
	Self-management support	Engagement in self-management Self-monitoring of pain Patient-provider communication
	Study nurse support	Value of nurse Timing of nurse support
Suitability of the intervention
	Impact on daily activities	Perceived burden
	Recommended usage	Appropriateness when ill Appropriateness when symptom-free Recommended usage
Recommended improvements		Additional self-management advice Additional gamified mechanics Tutorials on use Audio-visual assets Review data
Acceptability of the study
	General impressions and specific likes	General impression Specific likes
	Motivation for participation	Altruism Novel experience Gamification
	Challenge	Study phone