This hands-on workshop introduces an AI-assisted app development method centered on real-time voice interaction with large language models. Participants will observe and then practice a structured voice-first workflow for early-stage development: articulating constraints and success criteria aloud, iteratively refining requirements, and having the model generate and explain small, usable code components for classroom-ready CALL tools. Voice is used intentionally for ideation and specification, while code generation and implementation steps, such as testing, debugging, and deployment, are demonstrated using standard on-screen workflows. Successful examples, such as a randomized speaking-partner scheduler or an automated PDF region-extraction tool, draw on educator-built systems in Japanese secondary and tertiary settings, with attention to constraints faced by non-specialist programmers and common institutional limitations. Attendees will prototype a simple classroom tool or research utility with the explicit goal of building something they can “use on Monday.” Aligned with the 2026 theme “Prevail or Fail?”, the workshop emphasizes practical judgment: when voice interaction accelerates design and when it introduces friction. Participants leave with a working prototype, a workflow checklist, and reusable prompt templates. Laptop with Wi-Fi required; a smartphone or personal hotspot may be helpful for connectivity redundancy. A phone/headset is recommended.