This paper presents an approach to designing and testing a Wizard of Oz (WoZ) prototype that simulates Apple’s iOS VoiceOver screen reader for mobile devices. VoiceOver narrates on-screen content—such as text, buttons, images, and icons—enabling visually impaired users to interact with their mobile devices using gestures and voice commands. Despite its widespread use by the blind and low-vision (BLV) community, VoiceOver’s potential has been underexplored in Human-Computer Interaction research, particularly in the early stages of design. Using the WoZ methodology, where human facilitators simulate VoiceOver’s feedback, enables formative evaluations of BLV user interactions before developing higher-fidelity mobile applications. The paper begins by surveying the current landscape of voice-enabled prototype tools, identifying a notable gap in low-fidelity options for prototyping voice interfaces on mobile devices. To address this gap, we present a case study of Glide, a digital mobility device for BLV individuals. We detail how a class of senior design students developed a companion mobile app experience through an iterative design process utilizing WoZ. This approach surfaced key usability challenges to the app and informed subsequent design decisions.