I’m relatively new to Grammarly, an online proofreading tool, but I must say, so far, I’m impressed by its capability to make me a better writer. Recently they’ve also added a free browser extension that even now is helping me with my grammar and spelling. But the paid service is where Grammarly really shines. I’ve found it’s particularly helpful in catching the proper and improper placement of commas, (does anyone really know where they’re supposed to be used,) wordiness, and the improper use of words. For example, where you used it’s when it should have been its (as I did in a sentence above).