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)
I knew this app looks exactly like something else I've seen before, but I couldn't recall the name.
However, I don't consider this to be a copy of TeuxDeux because there's nothing particularly revolutionary in either app's design — they're both just digital versions of paper planners.
As far as todo apps go, I've tried them all. The problem I have with most of them is that they don't separate deadline with do-time. I want to plan a task such that deadline might be on Friday, but I intend to actually do the thing on Tuesday. Apps don't allow me to record that information.
When I first heard about TeuxDeux about an year ago I realized that the old fashioned and obvious weekly planner strategy could work. Since TeuxDeux wasn't free (I could be wrong because I now see a free version in their website), I just used a Google Doc to write down what I intended to do every day of the week.
And it worked reasonably well.
I'm happy to see WeekToDo come out. And it's open source!
Edit: we're kind of both right. $3/month, or $24/year.
More than one product can exist in a space (and todo lists are a dime a dozen) and maybe this was a completely original idea and GMTA, but wow it sure looks like a note for note copy