Yes, both VisibleThread and Grammarly Business offer a Free Trial.
VisibleThread is designed for Large Enterprises, Medium Business and Small Business.
Grammarly Business is designed for Large Enterprises, Medium Business and Small Business.
The starting price of Grammarly Business begins at $12.50/User/Month when Billed Yearly, while pricing details for VisibleThread are unavailable.
Some top alternatives to VisibleThread includes Linguix, Grammarly Business, LanguageTool, After the Deadline, WeTransfer, Wordsmith, EpicPxls and WriterZen.
Some top alternatives to Grammarly Business includes ProWritingAid, Linguix, WritingAssistant, Writer, PlagiarismSearch Checker, Ginger, Handywriter and PaperRater.