I was not aware of an Obtanium catalog like that. That's a nice feature that I see hidden at the bottom of the Add App screen. You can also use Obtanium to install from F-Droid sources and really just any apk, so it's superior in many ways, except in 1) discovery (which that catalog helps) 2) as devs aren't curating F-droid releases with care, sometimes it's a pain to setup, especially when a package is always `apk-latest` or something.