here are some atproto projects I think are pretty neat:
https://pdsls.dev/ -- wasn't the first atproto browser but IMO it's the best of the bunch these days. the PDS is normally pretty behind-the-scenes so this does a good job of bringing it to the front and letting people poke around these little KV stores in the sky
https://whtwnd.com/ -- the OG! a longform blogging app and the first non-bsky app built on atproto
its release was a big milestone, too: demonstrated the network could support more than just bluesky
https://www.graze.social/ -- best in class feed builder platform, love how forward thinking the group behind it is
https://frontpage.fyi/ -- HN-style link aggregator, first appview (IIRC) that wasn't a micro/macro blogging app
https://recipe.exchange/ -- recipe information stored as open, structured data? sign me up. great site design, too.
https://smokesignal.events -- an events and RSVP platform that also features some killer blog posts
https://github.com/lexicon-community/lexicon -- an effort to create community managed Lexicons so instead of apps creating their own custom street address record types (or whatever) they could use community.lexicon.location.address
https://github.com/ziodotsh/atfile -- doing silly things with blobs in atproto
https://bcounter.nat.vg/ -- tracks bluesky user registrations, has a ton of really fun touches like a confetti drop at big milestone numbers
https://blue.mackuba.eu/skythread/ -- good for reading really long threads and showing that different apps can make different calls on how to index the same underlying network (e.g., how to handle blocks)
https://blue.mackuba.eu/directory/ -- domains as handles are awesome! I still think it's cool as hell when I see a .gov
TLD
https://bsky.app/profile/xblock.aendra.dev -- people are addicted to bringing X screenshots into bluesky and this helps filter them out. really put some meat on the bones of "control your scroll."
https://bsky.app/profile/verified.moll.blue -- a fun little jab at all the people who joined in mid-November demanding blue checkmarks
https://github.com/mary-ext/atproto-scraping -- great resource tracking the network to find PDSs and labelers
I'm probably forgetting a bunch of other projects please don't take it personally. Check back often, I'll keep updating as I find new stuff.