As requested, I added a preference that lets you choose to hide the assignee parts of a chore list if you're not using them / the list is for one person. It's per-list so you can have a personal list and shared lists with separate settings.
There's better ways to have done this (adapt the UI to fit the fields better, auto-hide them unless you add more than one assignee, etc) but those are all more work and here at Froggy Chore we're all about Good Enough Engineering and No Guarantees Service.
Thanks for using Froggy Chore.
