An excerpt from http://www.sitepoint.com/10-free-ui-templates-android-lollipop-ios-8/, by @adaivanoff
A good PSD UI template cuts design time and effort in half and is a great alternative to starting from scratch. Here’s a list of my current recommended free PSD UI kits. Half are for Android 5, half are for iOS 8 with a focus on the latest versions of the two most popular mobile operating systems.
##1. Lollipop UI Kit
The Lollipop UI Kit from UXPin is one of the best Android PSD UI templates around. It contains 45 UI elements, including call screens, inbox, settings, etc. It’s available for Sketch, Photoshop and UXPin. You can download it for free once you enter an email address.
##2. Free Material Design UI Kit
This is an outstanding PSD UI template. This Free Material Design UI Kit is a Retina ready kit with design elements for almost everything, such as menus, search bars, settings, buttons, forms, calendar and more. As the name implies, this template follows the look and feel of the Google Material Design style. The layers are grouped, the shapes are vector and can be customized as needed.