"声で筆談" is designed to assist communication with hearing-impaired individuals who struggle with verbal communication. The app converts the speaker's voice (Japanese only) into text through speech recognition, enabling conversations via iPhone or iPad.

Conversations are managed in groups, each with a unique code to prevent cross-group communication. Groups can be easily created and disbanded, allowing spontaneous interactions by generating a group ID on the spot for individuals to join conversations instantly.

Users can save group IDs for recurring conversations with the same members. By pressing the Start button to speak, voices are converted to text and shared with all group members, displaying the speaker's name alongside the message. Participants and group size are easily visible, and text input via keyboard is also supported.