I thought I might share few of my current favorite add-ins. Love to hear from others...
* Daniel's XL Toolbox -- Daniel’s XL Toolbox is a free, open-source add-in for the Microsoft® Excel® spreadsheet software that helps you to analyze and present data and increases your productivity. (Free, Closed Source, Windows, Excel 32/64bit)
http://xltoolbox.sourceforge.net/ https://github.com/bovender/XLToolbox
* Excel Utilities -- Great Swiss army knife of Excel utilities (the website does not explain all the features well), Reset passwords, name manager for fixing errors, other powerful and useful utilities (Free, Closed Source, Windows, Excel 32/64bit)
The Excel Utilities Add-in
* Findlink - Find External links in Excel workbooks (in cells, data validation, conditional formulas, and more). Searches a workbook for a specified string (usually representing a link to another workbook) and tells you where in the workbook it occurs, optionally replacing formulas that include the string with their current values. (free, closed source, Windows, Excel 32/64bit)
FindLink
* Fast Excel -- Excel analysis and speed up utility (Commercial, Closed Source, Windows, Excel 32/64bit)
Why FastExcel V3 - Decision Models
* Excel File Cleaner -- Reduces the size and speed up Excel 2007 and 2010 workbooks. It will only work with the new XML file formats (XLSX and XLSM files). It cleans the files by reducing the number of styles in use and the number of activated cells.
https://excelfilecleaner.codeplex.com/ (free, open source, Excel 34/64bit, Windows)
* XLStylesTool - XLStylesTool uses Office Open XML file format based deep cleaning algorithm (patent protected). This means that it works 100+ times faster and is the ONLY option that can get rid of hidden and built-in corrupted styles inaccessible to other tools. (Free, Closed Source, Windows, Excel34/64bit)
https://sergeig888.wordpress.com/2011/03/21/net4-0-version-of-the-xlstylestool-is-now-available/
https://sergeig888.wordpress.com/