R: Great transparent boxes and font, interesting transparent background. Pro: icons, in particular text boxes. Gradient also works very well to create order/flow. Free cross-platform UI kit for Photoshop and Sketch
Livo UI Kit for Sketch & Photoshop is a modern, stylish, and intuitive kit for creating your app! This UI Kit contains more than 210 elaborate mobile screens in 8 categories. Each screen is fully customizable, & exceptionally easy to use!