Kutools for Excel - A handy Microsoft Excel add-ins collection to free you from time-consuming operations.
Yasai - YASAI is an open-source Monte Carlo simulation add-in for Microsoft Excel
Business Functions - Business Functions is a function library for Microsoft Excel that's been around since 2002.
Invantive Control for Excel - Invantive Control enables you to make decisions with Microsoft Excel and yet remain fully compliant...
Excel Dashboard School - Free Excel add-ins and tools on Excel Dashboard School. Boost your work productivity and save your time! No trials, 100% power!
@RISK - @RISK is the world's most widely used risk analysis tool.