Digital signature (eSignature) made easy with GroupDocs Signature. Create your electronic digital signature and digitally esign documents!...DOCM, DOTM Excel: XLS, XLSX, XLSM, XLSB, OTS, XLTX, XLTM PowerPoint:...\"ods\",\"ots\",\"xls\",\"xlsb\",\"xlsm\",\"xltm\",\"xltx\",\"csv\"...