Writefull- This link opens in a new window
It's a writing tool developed by a team of PhDs in AI and Linguistics. Its language feedback is more comprehensive and accurate than that of other tools and is tailored to research writing.
Writefull offers not only language feedback, but a set of widgets to help you write, including an automated Paraphraser, Abstract Generator, Title Generator, Academizer, a database of academic texts (Language Search) and a collection of example sentences (Sentence Palette).