Grammarly - Clear, effective, mistake-free writing everywhere you type.
Turnitin - Turnitin is preferred by educational institutions around the world for preventing plagiarism. Instructors at all levels of education can request that students use the service to submit papers, and Turnitin checks those papers for plagiarism.
LanguageTool - Free proofreading tool for OpenOffice, LibreOffice, Firefox, and Chrome.
iThenticate - Prevent Plagiarism in Published Works
Ginger - Powerful and effortless desktop & mobile solutions for improving your writing and productivity. Ginger Software is your personalized editor - everywhere you go.
Urkund - Detect and check for plagiarism with URKUND