Which app improved me in writing blog posts?

updated on 30 September 2020

Today, I have updated all my blog posts using Grammarly (Free) add-on for Google Chrome.  It corrected so many grammatical and punctuation mistakes I have made in the earlier posts and now I am extremely happy with it.
I have used Grammarly because of a Youtuber called Smart Telugu founder Mr. Ravi Kiran who beautifully explained it in his YouTube video which is added below. It is in Telugu Language but one can understand to some extent as it is in a visual presentation.
YouTube video from Smart Telugu: