Apps for GNOME
Opensource@kbin.social – 2 points – 
apps.gnome.org
Recently came across this page and was pleasantly surprised to see so many useful looking, modern and cohesive open source apps. Primarily targeted for use in Gnome environments but it's usually possible to get these apps in different desktop environments.
Just for completeness, KDE offers the same for their applications, which generally integrate well into any Qt based environment https://apps.kde.org/