There are many great content writing tools and apps available, each with its own unique features and benefits. Here are a few popular ones:

1. Grammarly: A popular writing tool that helps you catch grammar and spelling errors, as well as offers suggestions for improving your writing style.
2. Hemingway Editor: A web-based app that helps you simplify and clarify your writing by highlighting complex sentences, common errors, and passive voice.
3. Google Docs: A simple but powerful word processing tool that offers real-time collaboration, commenting, and revision history features.
4. Scrivener: A powerful writing app that helps you organize your writing projects, from research to final draft, with features like outlining, notes, and multiple document views.
5. ProWritingAid: A comprehensive writing tool that offers grammar and spelling checks, style suggestions, and a range of other features to help you improve your writing.

Ultimately, the best content writing tool for you will depend on your specific needs and preferences. It’s a good idea to try out a few different tools to see which one works best for you.