I used to browse through the latest apps on FDroid, but recently I’ve switched to using obtainium. There doesn’t seem to be a web interface that really shows the new activity or popular apps. I’d also be interested to see what’s happening outside of Android. How do you stay up on what’s happening in FOSS?
I prefer to do it via podcasts myself. The JupiterBroadcasting family have a bunch of variety to choose from in terms of what you like.
Changelog media is another good source to complement this rec. Longer form, as opposed to breaking news, conversations about many OSS related (and software development in general) topics. Some of their now defunct programs like Request For Commits were some of my favorites.
This Week in Linux is podcast that is more news-focused. It’s part of the TuxDigital network. The TuxDigital and Jupiter Broadcasting communities have a lot of overlap.