A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data
I don't use Xrealstats so I can speak to it — check the developer's support site.
Solver & Analysis ToolPak are Excel Add-ins provided with the program, so they do not appear in the 3rd party add-ins group on the Home tab. You'll find them in the Analysis group on the Data tab at the right end of the Ribbon. However, they should be usable from the Tools menu as well.