I have looked in all the right places and the only place they appear in in the extension MGR app. Actually there are a few that show up in the right places but the 2 that I used the most do not appear. I especially miss DR Russel.Browns helpers.
I had the same problem. Extension Manager is showing extensions for Photoshop CC 2014, Photoshop CC 32, Photoshop CC 64 and 'Others'.
Photoshop CC 2014 shows only one extension that is not in the Extension Manager list
I removed all extensions via Extension Manager in order to start again.
I installed one extension - but it does not appear in Photoshop where it should be.
I just noticed that in my CC panel I have this message for each of the extensions I tried to remove ...
"Installation failed, could not update database"