Objective:

To develop an application on primary nursing care for users with diabetes mellitus and to assess its usability in the light of the Unified Theory of Acceptance and Use of Technology.

Materials and methods:

A methodological study, which used a quantitative and cross-sectional approach, based on the Systematic Design of Instruction method. The product was validated for usability by 11 specialist nurses, using the System Usability Scale questionnaire, based on the Unified Theory of Acceptance and Use of Technology 2 by Venkatesh, Thong and Xu.

Results:

The application was developed through open and free frameworks, based on the updated content of the Nursing Protocol in Primary Care on Diabetes Mellitus, plus the International Classification of Nursing Practices in Public Health. In assessing usability, the application reached a score of 90 points, being classified on a scale of best achievable, with dimensions that ground the theoretical constructs.

Conclusions:

The technology named Diabetes em Foco (Diabetes in focus in English) is promising to improve and advance theoretical and practical knowledge, in addition to quick and easy access to the protocol, timely support for decision-making and strengthening the systematization of nursing care in primary health care.