Optionally Ideally it has 0 online features.
A checklist for when I’m leaving the house for the day to make sure I have everything
Paper checklists - I have to write out a new checklist every time and that really adds up as a time commitment, so being able to clear the checklist somehow is mandatory.
Simpletask
I think it’s also on Play, if that’s your thing.
It is available in differerent versions. There’s one with no networking, but also one with various cloud syncing, including self hosting (Nextcloud).
I’ve been using the offline version for years and syncing with Syncthing.
What I like most is that it uses the todo.txt file format, which IMHO is the uber-task-format, and means that I have a variety of editing options on the desktop.