Youglish

Perplexity is a free AI-powered answer engine that provides accurate, trusted, and real-time answers to any question.

Brainly is your AI Learning Companion that empowers students to thrive academically. Brainly creates responsive learning environment for students, parents, and teachers. Explore a world of questions and answers, test prep, and instant support from our AI Tutor, helping you learn smarter and do homework collaboratively for better grades.

ChatPDF brings ChatGPT-style intelligence and PDF AI technology together for smarter document understanding. Summarize, chat, and analyze.

通过渐进式挑战掌握英语 - 听说读写全方位提升, 挑战你的听力、记忆和拼写能力，通过系统化的重复练习，将英语知识转化为肌肉记忆。