SparkleStore is my favorite WordPress theme. It is fully responsive and is highly customizable. It is a newer theme with relatively smaller installation base. I have used it and never had any problem with it.
Following comments are taken from WordPress website.
Sparklestore is a clean, beautiful and fully customizable responsive modern free eCommerce, WooCommerce WordPress theme. It is esthetically minimalist, fresh-faced and bright, elegantly styled and well developed, readily responsive eCommerce WordPress store theme.
It is a perfect theme for commercial endeavors of all kinds, from digital download shops to online commercial retail of all kinds. It integrates the industry standard WooCommerce, YITH WooCommerce Wishlist, YITH WooCommerce Quick View, WOOF Products Filter for WooCommerce, WooCommerce Variation Swatches, Jetpack, Contact Form 7 and many more plugins, a wonderful solution for all your online commerce needs, which allows your users to browse your product catalogs or store in easy but stylish grace, add items to their shopping carts intuitively, and proceed to checkout and make payments, all right off your website.
Sparklestore is a beautiful and a compatible theme for WooCommerce based ecommerce websites. It has lot of beautiful widgets to quickly build gorgeous home page for your ecommerce website. It also has pro version which can be used for better support and higher customizability. The store we have setup does not require pro version and is fully functional with the free version. Try it and decide by yourself.