To locate ggv, if it exists, you can use several tools; here are two ways of doing it
if the (s)locate database was updated after you installed ggv, this works. If you have not updated the database (or are not sure if you have) after the installation of ggv, run the below command as root to update it (otherwise skip that):
After that locate the ggv file:
If there are a lot of results, you may try to use (for example) grep to cut down the hits:
locate ggv | grep bin/
The above would only show those locate hits that include bin/ in their name (hopefully just files that are under some binary directory).
This may or may not be slower than the above method, depending on where the file is, where you begin searching and so on. But it should work, and that's the good part. The switches used are: '--type f' to search only "regular" files (not directories etc.), '--name' for the name to search, maybe with wildcards if you like. Note that here we start searching from the root of the filesystem ("/"), but you can start from other directories as well; the search is recursive.
find / -type f -name "ggv"
Again you can use grep like in 1) to cut down the list of found files, if you get loads of results. You shouldn't, though. For more options
Once you find the command, run it with full path and it should launch, and/or add the path to your $PATH environment variable to be able to run ggv without full path - or if you can't find it, it's either named to something else than "ggv" or then not installed at all.
As a last thing I mention what I should have mentioned first: read man pages
if you installed ggv, most likely it installed some man pages as well, which reveal the program name and so on..
or if that didn't give any results,
and start searching.