First impression: really works for what is intended. And it works well.
Suggestion: Allow visitors to hide or close the bar. Auto hide after X seconds. Position: header/footer. And all that admin can select from Yes/No.
Advantage: Plugin is simple. Responsive. Displaying on the homepage, on single page, all pages. Showing: certain days or permanently.
Disadvantage: the button "save" are seen only half. As it was cut horizontally. Maybe you've played too much when you're doing the design, but that's just my subjective impression. Desired is a simple design.
Go ahead, this is great!