AC Log has a Watch list under the file menu.  You have to create a file, which I can upload if anybody wants it , of call signs that you want to be alerted to.  The alert is a pop up window that is activated when you enter the call sign into the Call field.in either the AClog field as stand alone or the FLDIGI call field is you use it with FLDIGI.  AC Log also has a DX spotting function that can be configured to use the watch list and activate the pop up window alert if the call sign is spotted.

In my opinion I liked the alert feature in DX Keeper better, but I decided to buy AC Log last year because I could not get the gateway between FLDIGI and DX Keeper to work with windows 10.

I hope that helps.

Bob
KK6KMU