FireFlies

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。

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

Master English Pronunciation Like a Native! YouGlish (100M+ clips).Struggling with English pronunciation? YouGlish uses real people speaking real English to help you master tricky sounds. No more dictionary confusion!