Cloud APIs & SDKs for adding Watermark for Microsoft Excel & OpenOffice Calc. Adding Watermark for local spreadsheets by the Cells Cloud API. SDK support kinds of development languages. They include Android, C#, Go, Java, NodeJS, Perl, PHP, Python, Ruby, and swift....Background ADD-WATERMARK Background Ruby API to add watermark for local...spreadsheet Ruby library to add watermark for local Microsoft Excel...