Viper

Five stars! In college whenever I was writing big papers I always sued this tool. It's really easy to to mistakes certain parts for not plagiarism but with this tool I know for sure what should be left, what should be quoted properly and what should be cut down. Actually, before I found Viper I briefly used such plagiarism checkers as Copyscape from https://www.copyscape.com/, plagiarism checker from https://www.grammarly.com/ and another plagiarism checker from https://jetwriters.com and based on that Viper is quite good since it's free and it doesn't leave plagiarized parts out. And that's what matter!! Kudos for the Viper creators!!