I swore I deleted that app

How do I know an app is really gone after deleted. I know, it should be gone after just moving it to trash. But here is the thing. Over a month ago I deleted a free app I never used. It was a task manager called Anxiety. I forgot about it until I just checked my start up programs in System Preferences and Anxiety is listed as one of my start up programs. So, there is some part of it that stayed behind. I could just delete it from start up programs there but I don't know if it still may be hiding somewhere else. I couldn't find anything with spotlight.

Anyone know where I should look for it. Or, if it is really gone? How do I know for sure? Thanks

Not familiar with that one, but any app that installs via it's own .pkg utility rather than drag and drop, you need to use it's uninstaller.

If that's the case with this one, download it, install it again, and then run the uninstaller.

Well-named app there.