Ask HN: Looking for the lightest and most basic digital to do list

Before I spend tonight either making a command line to do list or a lightweight web app - I was wondering if any of you guys had made one or had any suggestions

Ideally - Free - add, complete, view complete - lightweight - command line or web-based

Google Keep works in mobile and desktop. It's $free.

I sometimes use Whatsapp (Android) as a fast multimedia todo app. The way it works is that I create a group where I am the only member. I then add an icon on the home screen that immediately takes me to the group so I can start typing, recording voice, taking photos, etc. It doesn't have task statuses or even checkboxes, but it can manage lots of different data formats.