I use Microsoft ToDo, sharing would be an option (requires an MS account for both)

I don't think an app exists.
You can try with your Browser (Firefox if others don't work) and Power Delete Suite - installation/ running is the image at the bottom.

Pi-hole, Wireguard + 'a CDN client' on raspberry pi 4 with SSD
Ditched my Synology NAS, running an unRaid machine now:
i5-10400, 32 GiB (to much) Memory, 15.7 TB used of 60 TB

• VMs: homeassistant , macOS, Windows 10
• SWAG, Cloudflare DDNS, Arrrrrr dockers, Plex, ArchiveTeamWarrior, gokapi, qBittorrent, Resilio Sync, wikijs, mariaDB + whatever I find interesting to try out

Agree - Mastodon has lists, would like this too for Lemmy (even though I've not used them so far)

The project just started and as far as I can tell they have uploaded some 'random' videos so far.

https://github.com/sr33/ares - Nuke Reddit History (Chrome and Firefox extensions/ addon)

Not sure - could be because it's the 'official' one and not a community server.

On 2nd look - I see lemmy.ml comms, could have been a 'hickup'

Manjaro Gnome, on laptop and desktop