Proser is a GPT which acts as supportive writing coach. It is designed to help users with various aspects of writing by providing its users the necessary guidance and encouragement to start and continue their writing journey. As a GPT, Proser operates on top of ChatGPT, capitalizing on the latter's language modelling capabilities to facilitate and enhance user interaction. Moving beyond the capabilities of a conventional writing tool, Proser takes a proactive and empathetic approach. It addresses common writing issues such as writer's block, procrastination, lack of motivation, and inefficiency in structuring thoughts. Using creative prompt starters like 'I can't seem to start writing.', 'How do I stop procrastinating?', 'Can you give me a writing prompt?', and 'What's a good writing routine?', Proser engages writers and helps them find the right mindset and routine to begin their writing process. Proser also comes with the potential of promoting a regular writing habit among users. It supports the users by providing a welcoming atmosphere - showcased through greeting messages such as 'Hello! Ready to start writing today?'. Overall, Proser represents an innovative use of AI-powered GPTs to provide an interactive, supportive, and effective solution to address various writing challenges, thereby enhancing the writing experience of its users.