I guess calling it an app and saying that I own the data made me think it was an electron-app or something.
If I can't export the data (I see nothing about it) and it's not stored on my device I think it is a stretch to say that I own my data. I get that it might not the first feature to implement, but for the future that is something that at least I would expect.
A number of people have commented that Google login only is a barrier, so will definitely be adding another signup method.
The source is on GH with instructions to spin up your own instance if you prefer.