@ MeoKhan: Thanks. I am mainly concerned about two specific things of the software: efficiency (it can detect possible plagiarism) and reliability (my write-up will not be leaked). From your reply I think I got answer to both.

Does anybody have idea about this site : dustball.com/cs/plagiarism.checker/

It allows free checking of small write-up (may be upto 2-3 paragraphs), and if you purchase the monthly cost is $ 8. It appears to be cheap than turnitin.com, if you have long article or have more than one article to check. I am not sure about the quality or reliability of dustball.

Can anybody give me some more information about this site?