If you're looking for a Fixkey alternative, Wordvice AI is definitely worth a look. It's a full-featured suite of AI writing tools, including an AI Proofreader, Translator and Paraphraser that can help you improve your writing in many ways. It supports multiple languages, so it's a good option if you need to write in different languages. Wordvice AI also integrates with MS Word for a smooth writing experience.
Another good option is ProWritingAid. It's got a lot of AI-powered tools, including style and structure checks, grammar and syntax improvements and even plagiarism checks. It works with Microsoft Word, Google Docs and Scrivener, so you can use its tools in whatever software you prefer. ProWritingAid offers a few different pricing levels, so it's useful for both hobbyists and pros.
If you want a more personalized writing assistant, Reword is another good option. It personalizes its help based on your writing style and offers coauthoring, fact checking and SEO optimization. Reword supports more than 25 languages and works with a variety of content management systems, so it's a good option if you're writing for different situations and audiences.
Last, Kerlig is an in-context AI writing assistant for macOS similar to Fixkey. It offers grammar and spelling checks, research help and support for multiple languages built into whatever app you're using. Kerlig supports multiple AI models and offers a range of customization options, so you can fine-tune the AI help to your writing style.