Blood donation is a social practice that helps treat diseases and maintain public health. The DoeSangue application was designed and developed to support donor recruitment and loyalty, strengthening health promotion and social engagement. We aimed to assess the DoeSangue application from the perspective of hematology and hemotherapy experts. A methodological, applied and qualitative research was carried out from September 2015 to July 2017 in Fortaleza, Ceará. The study was based on Participatory Interaction Design associated with Symbolic Interactionism. After conducting the first two steps, application design and development in a laboratory and assessment by donor users, the application was validated by eight experts from the Fortaleza's public blood center. For data collection, the 'application validation form with experts' was used based on a Likert-type scale, and a focus group was conducted. The tool was positively assessed by participants, with an average Content Validation Index of 0.88. Evaluators pointed out, among other features, the tool's ability to promote interactivity, mobilization and social engagement, in addition to contributing to gathering and loyalty of blood donors.