I fear this site is not ready for "the world" just yet. I HAVE put things in the headers trying to avoid it being spidered!
Filezilla (Client and server)
Open Office- not least for the database that come with it. Or Libre Office. (I happen to be an Open Office user, but believe (on limited actual knowledge) that Libre Office is the same in the things that matter to me.)
This category blurs the focus of this site. Of course, there are many, MANY good web sites out there! I am listing things which are almost like having an app on your PC, in spite of being web-hosted.
Many can be used in offline mode, further confusing the issue!
Spotify... so far, I've only used the "free" version, but that may change before long. Free gives me most of what I want, but the ads are beginning (after months) to grate. And the "extra bits" that come with paid for would be nice. But they're not not "necessary". (Not that streaming music is "necessary", of course!))
TunnelBear... worth it for the whimsical graphics alone!
Sorry... I know you know of great apps, too. But I have no way of distinguishing the genuine recommendation from a knowledgeable user and a self serving recommendation, however sincere, from an app's developer... and thus I won't be adding apps to this list that are not known to me.
And "sorry, two": I apologise to everyone out there who, like me, cringes as the degradation of the English language. If I could have put an apostrophe in the URL, I would have, and I know I could have called the site "ThereIsAnApp.com". But "There's" is what people say, even if the syntax rules don't allow me to put the apostrophe in the URL.
Tested using the free validator at validator.w3.org for compliance with industry HTML standards. Mostly passes.