It's a very simple weekly planer. There is going to be columns with weekdays and in those list items. There are a lot more than these two apps in this space. I personally enjoy https://tweek.so/

The privacy and locally hosted angle seems like plenty of differentiation.

Other than that I'd have to squint very, very hard to make it look "exactly" like TeuxDeux (which I find a lot less appealing, visually)