TeXtidote
Spelling, grammar and style checking on LaTeX documents
If so, you probably know that the process is far from simple. Since LaTeX documents contain special commands and keywords (the so-called "markup") that are not part of the "real" text, you cannot run a grammar checker directly on these files: it cannot tell the difference between markup and text. The other option is to remove all this markup, leaving only the "clear" text; however, when a grammar tool points to a problem at a specific line in this clear text, it becomes hard to retrace...