On android (though I wish I was using a true gnu/Linux phone…) I open Neo store every once in a while and peruse the explore tab, sorting by most recently updated. Neo store is a better f-droid client (a source for open source android apps)
For desktop Linux, i guess you could do the same, (though for some reason i haven’t) and peruse the free sofyware marketplace that comes with your linux distro. I also used to google articles about top 10 new open source apps for ubuntu 2023, or similar google searches. I also used to read a bunch of Linux, open source, and linux hardware related sub-reddits that I’ve been slowly trying to replace with Lemmy communities, right now I subscribe to:
C/f-droid
C/hardware
C/homelab
C/Linux
C/linuxhardware
C/opensource
If anyone has anymore I should subscribe to, suggest away!
I also browse YouTube which in the past has suggested videos of people reviewing new open source apps or software. Though those video suggestions have gotten worse as YouTube’s algorithms have gotten worse in the last few years.
Also in the past I’d peruse alternativeto.net to see if there’s anything better in the open source world for proprietary software, or even alternatives to existing open source software I use.