Textbuddy's Plain English Text Analyzer Tool is a free tool that helps users to improve their writing by analyzing their text and identifying areas that could be clearer and more concise. The tool offers a range of features including grammar and spelling checks, passive voice detection, complex word detection, filler and vague word detection, formatting errors detection, synonym suggestions, sentiment analysis, keyword density calculation, and a readability score. It also has an AI assistant that can help users with grammar and spelling, create headlines and summaries, rewrite text in plain English, and analyze text sentiment.