QuillBot is a broad AI-powered writing assistant that offers paraphrasing, grammar checking, plagiarism checking, summarization and translation tools. It also has an AI writing assistant and a citation generator, so it's good for writers of all kinds. The Premium subscription adds features like unlimited paraphrasing and custom summaries.
Another good option is Wordvice AI, which offers a range of AI-powered tools including a paraphraser, translator, summarizer, plagiarism checker and AI detector. It's good for researchers, students, content writers and businesses, with a range of subscription options depending on your needs. It also offers MS Word extensions and expert proofreading.
If you're looking for an all-in-one content optimization platform, NeuralWriter is another option. It offers a paraphrasing tool, summarizer and paraphrasing API supporting more than 27 languages. The platform also offers a ChatGPT prompt generator, headline generator and word counter, so it's a good option for content creators.