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.
Grammarly - Clear, effective, mistake-free writing everywhere you type.
iThenticate - Prevent Plagiarism in Published Works
Hunspell - Hunspell is the spell checker of LibreOffice, OpenOffice.
Plagramme - Our plagiarism checker recognizes paraphrased plagiarism, checks your paper against more that 14 trillion documents and lets you to edit your paper online.
DSpellCheck - Yet Another Notepad++ Spell-checking Plug-In