Table 3.

List of app functionalities.

Main features (ideated)	General description (ideated)	Subfeatures (refined based on considerations from stage 1 and the CALO-REa constructs)
Training plan	Activity program guided by the PAb guidelines and recommendations for breast cancer survivors; based on linear progression training; with adaptable levels; visually represented by an activity schedule; includes reminders for activity.	Information about PA program, guidelines and potential benefits for the users; a plan that sets the number of activities per week and its duration and difficulty; a weekly activity schedule; baseline assessment for current PA level; assessment of perceived difficulty; adjustable plan level; push notifications and reminders for activities scheduled; push notifications and reminders to review the plan and reschedule activities.
Adaptive goal setting	Activity objectives adjusted to the user.	Present the user with clear daily objectives in the main screen; set achievable but challenging goals; progress bars; inform of long-term benefits of achieving goals; present automatic adaptation to the user’s profile information, progress, user’s perceived fatigue and perceived difficulty; notifications of goal adjustments; weekly goal adjustment.
Real-time monitoring, feedback, and motivation during activity sessions	In-session or ”workout” coaching; visual and easy to understand; combines real-time monitoring, feedback and motivation.	Predefined walking sessions; guidance to meet the session plan; intuitive interface to provide session information; shows the session progress (time); shows the user’s pace in real time through a glanceable visual display; sends cues to control the pace; provides positive reinforcement and recognition; coaching cues are in textual and audio format; shows achievements when the session is concluded with a breakdown of the session: steps taken; calories burned; distance walked and session duration.
Activity status through the day	Feedback on the total activity performed until that point in the day and progress toward the daily goal.	Screen with numeric representations of active time: steps taken, calories burned and distance walked; progress bar showing progress toward the daily goal; option to manually entry activity; encouraging pop-up messages.
Activity history	Tracking past activity; graphic display; simple and intuitive.	History screen; bar chart representation of daily activity in relation to the goal; week-by-week information.
Periodic summary reports	Descriptive summary of the activity performed during the week and the overall progress in the program; tips for improvement; motivation to be active and to follow the program.	Weekly activity reports; presents a breakdown of the activity performed during the week; bar chart representation comparing current week activity with previous weeks; communicates progress in the plan; encourages users to follow the program; provides tips according to the user’s physical barriers; informs users of PA benefits.
Challengesc	Unexpected activity challenges.	—d

^aCALO-RE: Coventry, Aberdeen, and London—Refined taxonomy.

^bPA: physical activity.

^cTo be considered in future iterations of the prototype.

^dNot available.