ComposeMate is an AI-powered Chrome extension designed to enhance email writing by integrating with Gmail and Outlook, and offers the flexibility of adding custom email providers. Built on the GPT-3.5 API, this tool introduces effective email writing tools to assist users. Its key offerings include autocomplete and tone detection; autocomplete completes sentences while typing, aiming to reduce time and stress, and tone detection recommends the optimal communication tone to utilize based on analysis of current text. This tool is customizable, allowing users to tailor its use according to their unique needs and preferences. By using ComposeMate, users can maintain full control over their data and usage, as it allows them to integrate their own OpenAI API keys. ComposeMate's mission is to not only speed up the email writing process and make it less stressful, but also to enhance communication quality, build better client relationships, and thereby increase overall productivity. The access to this tool is provided with a one-time payment. The functionality of ComposeMate necessitates enabling JavaScript settings in users' browser.