You can control the availability of add-in functions using two check-boxes in the XLL+ Function Wizard:
At least one of these check-boxes must be checked.
Worksheet functions can be called directly from Excel worksheet cells. They will be registered with Excel as "Type 1" functions. If you do not check the Worksheet Function check-box, the function will not be available from a worksheet.
Worksheet functions cannot usually call a number of Excel SDK features, including the ability to inspect the contents of cells other than the function's arguments. If you wish to make use of these features in a worksheet function, then you should use the DeferRecalc setting.
A macro function can be called from VBA code using Application.Run().
If it takes no arguments, it may also be called directly from an Excel menu or push-button. See CXlMenu in the Reference Guide to find out how to add menu items to the Excel menu bar.
Macro functions will be registered with Excel as "Type 2" functions. If you do not check the Macro Function check-box, the function will not be available from a menu or push-button.
A function that is marked as both Worksheet and Macro will be available in both contexts.
Such functions will be registered with Excel as "Type 3" functions.