Question: I need a writing assistant that can provide instant feedback and suggestions to improve my writing quality.

PaperRater is an AI-powered tool that can give you immediate feedback on grammar, spelling and plagiarism. It also offers writing tips and can give you a grade on your work. The best part? It's free, with results in 5-15 seconds and no download or sign-up required. Premium features are available with a subscription starting at $14.95 per month.

Another good option is Wordtune, which is designed to help you be more productive and confident when writing across different channels. It offers tools like AI suggestions for rewritten text, personalized writing prompts and an AI summarizer. Wordtune integrates with Google Calendar and Microsoft Word, and it's available on desktop, mobile and the web. It offers a free tier, but more advanced features are available with its more expensive plans.

Last, Wordvice AI offers a range of tools to help you improve your writing, including an AI proofreader, paraphraser and translator. It's geared for researchers, students and content writers who need to produce high-quality work fast. Wordvice AI offers a range of subscription plans, including a free basic plan, depending on your needs.