A new version of Topo vertex maps is in the works (2024).
For the the old version .....
In general, on MAC, for R15 it is best to install any plugin to the user/plugins folder.
on a PC, or pre R15 MAC, you can install to user/plugins or APP/plugins , it does not really matter which.
Topo Maps contains 2 custom tags, and these can be found in the standard tag list.