We would like to share our insights in designing, preparing, preforming, and analyzing usability tests for multiple connected augmented reality and virtual reality applications as well as traditional mobile applications developed for a multimodal screening tool. This screening tool is under development at the University of Applied Sciences FH JOANNEUM in Graz, Austria. Several researchers from the departments of health studies and applied computer sciences are working closely together to establish a tool for early diagnosis of cognitive impairments to contribute to the management of dementia. The usability of this screening tool was evaluated by ten therapists paired with ten clients as testing group 1 and two usability experts in a separate test (group 2). In this chapter, we would like to describe why we use observed summative evaluation using the co-discovery method followed by post-task questionnaires for the first testing group. We are going to discuss the reasons for performing the cognitive walkthrough method as co-discovery with usability experts of testing group two as well. Furthermore, we describe how we use camera recordings (traditional cameras, 360-degree cameras), screen recording, and special tailor-made software to experience the screening process through the user’s eyes.