I have it installed. But the only thing I get updates for is Obtainium itself. There's no catalogue of apps, so I haven't installed anything via Obtainium.
https://apps.obtainium.imranr.dev/
They put the disclaimer on top that this list is not meant as an app store or catalog. It's meant for apps with somewhat complex requirements for adding to Obtainium. But it serves well as a catalog since most of the major open source apps are listed.