Back in the day, I used DragThing to group apps. Alas, it is no more. There are similar dock enhancement / replacement apps, allowing one to group apps based on context or domain, but I do not use them so I cannot recommend any particular one.
Today I use Alfred as my app launcher, and don’t worry about such app management, apps are just in the Applications folder. I also use Bunch to launch sets of apps based on what I want to do.
Finally, I use the Comments section of the Get Info window to note what the app does, along with the URL of the developer’s website.