While I will withhold my view on such apps, do try the following:
1. Use Revo Uninstaller (the free version is fine) and see if it sees it.
2. Hit up Bleepingcomputer.com as they have an arsenal of tools they use that we don't use here.
I recently downloaded and installed Windows keylogger 3.1.4 and I'd like to remove it. This software doesn't show in task manager, I cannot find it in the control panel, nor can I find the folder associated with the software. I've tried their website, but all the links are page 404 not found. I would very much like to fully remove the software.
Keep in mind that it is unlikely that you've get a click by click how to remove this one. You could do the old manual uninstall where you delete it's program folder then look in AUTORUNS to remove it's autostart entrie. AUTORUNS is a Microsoft tool at https://docs.microsoft.com/en-us/sysinternals/downloads/autoruns
And you could try Bleepingcomputer.com too.