Watch App UI

This is a sample UI for a watch selling app. It has a classy look, and gives a vibe that the watches suit for the corporate guys.
The black-yellow theme gives it a modern look and the combo of Serif font for heading with Sans serif for the body provides the contrast.
Visual grouping of contents is maintained throughout the UI.
The 'Buy Now' button hovers over the screen all the time so that if the user makes his mind to buy at any point of time, he can do it with just a click.
How is it? Put your thoughts on this on the comments.