Screen Sizes - A complete guide for Apple displays
MockMagic - A free, easy-to-use device mockup generator
Device Shots - Generate high-resolution device mockups using a screenshot.
Dimmy.Club - Device mockup generator for your website and app screenshots
AppLaunchpad - Create free beautiful screenshots for App store/Google play
Mockup Generator by Pixeltrue - Create beautiful product mockups in just a few clicks