Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
XLS to XML - XLS to XML is the name of a portable and cross-platform application for converting the XML file to the XLS and vice versa.
Magic Spreadsheet - Human workforce and AI plugged into your Google Spreadsheets
XML Converter Standard Edition - XML Converter Standard Edition is a way to transform the data stored in the XML format to XLS format within few minutes.
Spreadsheet.com - Spreadsheets that come alive as applications
ZAMZAR XLS to XML - ZAMZAR XLS to XML is the web based free conversion system by the ZAMZAR that support for the multiple file conversion.