A trick, with some drawbacks, is to open your top level vi, and while holding the shift and the Ctrl keys, click on run. It will show the hour glass for sometime (the more sub-vi's the longer). When the hourglass goes away the vi won't be running, and if you select "Close" in the file menu you will see a message telling you that many vi's need to be saved. If you select to save the sub-vi's they will all be given the same time stamp, which makes sorting them out much easier. The previously mentioned drawbacks are: 1) you loose the individual timestamps, which might be important in tracking your work, 2)it does this to "all" the vi's loaded in memory, so even ones in the native LabVIEW directories will have their timestamps changed. 3)It doesn't do this to those vi's that are dynamically loaded.
A technique to help with #1 is to make a copy of the that you are doing your development work in, perform this on the copy and then use a listing of the new directory (or delete all the ones in the new directory with the new timestamp) to look for those used/not used. It doesn't answer the issues of 2 and 3 though.
Putnam Monroe
PutnamCertified LabVIEW Developer
Senior Test Engineer North Shore Technology, Inc.
Currently using LV 2012-LabVIEW 2018, RT8.5

LabVIEW Champion