Whois based country flags
One of the features that 4chan has on /int/ and to a lesser extent /pol/ that I think would be a nice addition to Pleroma is attaching small national flags to posts based on the location of the IP. Considering how widespread the userbase of Pleroma is, and given that I can't remember what country half of the people I regularly interact with are from, I think it'd be nice to be able to glance at a small flag and know that Mitsu is in Spain and Nepfag is in Switzerland. It would also aid in reminding Americans that most of the people they're talking to aren't directly subject to US politics.
Obviously, there would probably be some objection to such a feature on privacy or other grounds, so I would propose that users and instances be able to opt out through their profile settings in the case of users, and through *.secret.exs in the case of instances. I say opt out because I feel like such a feature would be largely useless if it had to be enabled in the settings. It would be better to have it enabled by default and allow users and admins to not participate if they so choose.
Moonman has done something similar on SPC with icons for instances attached to posts, so that might be a good starting point.
Disclaimer: I am not a programmer nor a Linux expert (I barely qualify as a Linux user), so I probably can't elaborate on the technical aspects.