Search notes:

Excel: File -> Options -> Add-ins -> Manage -> COM Add-ins

Add-ins I've seen available under File -> Options -> Add-ins -> Manage -> COM Add-ins include

Acrobat PDFMaker Office COM Addin
Inquire	Adds the menu Inquire
Microsoft Azure Information Protection
Microsoft Data Streamer for Excel	Adds the menu Data Streamer
Microsoft Office PowerPivot for Excel 2013	Adds the menu Power Pivot
Microsoft Power Map for Excel
Power View