TweetCheck is an Artificial Intelligence (AI) powered tool designed to monitor and correct grammar and spelling errors within Twitter and X posts, comments, and messages. Targeted at enhancing the clarity and professionalism of Twitter and X communications, this tool is capable of checking both short tweets and detailed posts. A notable attribute of TweetCheck is the personalized correction experience it offers. The user can tailor the AI's correction style to align with their tone and preferences via customizable prompts. Additionally, TweetCheck employs several ChatGPT models for text correction, providing the user with a range of options suitable for diverse needs. Commencing usage involves a simple setup process, where the user provides their OpenAI API key. To ensure personalized corrections, the user can customize the prompt and select the AI model of their choice. Regarding data safety, TweetCheck does not collect or store personal data; settings and API keys remain local to the user's device. It stresses a strong commitment to user privacy and security.