Artificial intelligence (AI) technologies have contributed significantly to the advancement of society. In recent years, AI-powered writing assistants have received increasing attention among English as a Foreign Language (EFL) communities. However, most of these digital writing tools focus on the revision and editing stages. Few digital tools are developed to help users during the writing process, such as assisting users in formulating or translating their ideas into writing. Wordtune is an AI-powered writing assistant that understands the writer's ideas and suggests options for rewriting them using different tones (e.g. casual, formal) and lengths (e.g. shorten, expand). This tool can help EFL writers maintain a continuous flow and learn useful ways to express their ideas in written English. This tech review aims to provide an overview of Wordtune and its affordance in English writing for EFL writers, while also addressing the benefits and limitations of this technology.