Table 1.

Professionals’ assessment regarding the usability and functionality of the mobile app prototype.

Evaluation items	Experts’ levels of judgement (N=8)					Concordance index (%)a
	No	In parts	Not sure	Yes	Certainly
1. It seems to be easy to understand the concept and manipulation of the app.	0	0	0	1	7	100
2. The app appears to be self-explanatory.	0	0	0	0	8	100
3. The tutorial is useful to optimize the use of the app.	0	0	0	1	7	100
4. The organization of the menu is logical.	0	0	0	1	7	100
5. Icons are clear and intuitive.	0	0	0	1	7	100
6. The look of the app (design and layout) is attractive.	0	0	0	2	6	100
7. It appears to be easy to navigate the app screens.	0	0	0	1	7	100
8. The sequence of actions in the app is consistent.	0	0	0	1	7	100
9. The app has useful functions.	0	0	0	2	6	100
10. The app appears to be accurate in performing its functions.	0	0	0	1	7	100
11. It seems easy to find information in the app.	0	0	0	2	6	100
12. It seems easy to insert personal information in the app.	0	0	0	2	6	100
13. It seems easy to insert events and medications into the app.	0	0	0	3	5	100
14. The texts in the app are easy to read.	0	0	0	2	6	100
15. The illustrations are important to complement the texts and facilitate the use of the app.	0	0	0	0	8	100
16. The screens are visually pleasing and seem to encourage the use of the app.	0	0	0	1	7	100
17. Using the app seems simple and accessible.	0	0	0	2	6	100
18. It seems possible to maintain interaction between the user and the app.	0	0	0	2	6	100
19. The app can be used by users of different educational levels.	0	1	1	4	2	75
20. I believe that most users would learn how to use the app.	0	0	1	2	5	88
21. The app can be used anywhere, such as at home, hospital, or street.	0	0	1	1	6	88
22. I would recommend the app to be used by women with breast cancer undergoing radiation therapy.	0	0	0	0	8	100

^aConcordance index was calculated by the sum of yes and certainly judgments: (Yes+Certainly)×100/total of responses.