Check Plagarism @Viper
It is a good practice to always check the level of plagiarism of your paper in case you forgot that there are some sentence that you copy paste without rephrase it. Before this LS used Turnitin but because it is a paid service than LS turn to Viper. LS used it to check student work. So far so good. You can try it out by download it here: Click this link
Viper Interface
Viper Report