Epic's Unreal Engine 4 Rivalry project shows what's now possible on mobile devices.
Physics-Based Simulations and Effects in Unreal Engine
Sam Dieter and Tim Hobson deconstruct simple physics-based simulations and effects available in the Learn tab of the Unreal Engine launcher.
Unreal Engine - Open World Demo Collection - Free
Epic Games are giving away assets from their Open World demo, to be used within Unreal Engine 4 based products.
Unreal Engine Marketplace Adds Free Mixamo Animations
Mixamo has announced that a collection of its animations and 3D characters are now available for free in Unreal Engine 4.3.