Custom Functions in Excel

This Excel add-in provides additional worksheet functions that will increase your productivity.
If you are familiar with VBA user defined functions then this add-in is definitely for you.
These functions can be used in your regular formulas to help perform data analysis and data manipulation.

Features
Over 50 additional worksheet functions.
Add sample data quickly for faster learning.
Replace all the functions with formulas or values.

Examples
SpellNumber(23) = "Twenty Three"
SpellNumber(4681) = "Four Thousand, Six Hundred and Eighty One"
COUNTFORMAT
DAYSINAMONTH
SPELLNUMBER
SUMFORMAT

Download from the Office Store

Microsoft AppSource is an online store that contains thousands of business applications, add-ins and services.

link - appsource.microsoft.com/en-us/product/office/WA200006253 

You can access this store from inside every Office application by displaying the Home tab and selecting Add-ins.

AppSource has a dedicated catalog for each of the different Office applications.
You can browse the store

link - appsource.microsoft.com/en-us/marketplace/apps?page=1&product=excel