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?
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.