nextcloud provides apps for both calendars and lists, if you’re comfortable getting into self hosted services. of course, there are a number of other self-hosted apps that provide similar functionalities as well, but nextcloud is probably a good place to start
Check out Lychee. It’s designed for (semi) public photo galleries more like Flickr
I recently switched from Google Podcasts to Podcini (fork of Antennapod) and it’s great so far
NixOS
I love NixOS, but the documentation is terrible. Better documentation would go a long way to making it a more user-friendly platform.
I really like immutable distros, and am currently using NixOS. I feel like despite still being relatively obscure, NixOS is a bit of an outlier since it has more packages than any other distro and is (so far) the only distro I’ve used that has never broken. There is a steep learning curve, and I certainly wouldn’t recommend it for non programmers, but it is something truly different than all mainstream Linux distros while being extremely reliable.