A Google Webkit Speech Recognition developer primarily works on integrating and enhancing the speech recognition capabilities in web applications. They utilize Google's Webkit Speech API to enable web applications to translate spoken words into text, providing hands-free interaction and enhancing accessibility. They work on designing, implementing, and testing these functionalities, ensuring they work seamlessly across different devices and browsers. They also troubleshoot issues, optimize speech recognition accuracy, and constantly update their knowledge on evolving speech recognition technologies. As part of the job, they collaborate with other developers to ensure a cohesive user experience.