Promomatic - Easily create beautiful app store assets
Josh Parnham - Software Developer and organiser
AppLaunchpad - Create free beautiful screenshots for App store/Google play
Yoink - Yoink is a website that makes it easier to drag and drop images and text from one screen to another. It's a straightforward site with help along the way if you aren't sure about dragging and how to place your content.
DaVinci Apps - Сreate customized screenshots for your app in just 3 steps
ScreenFloat - Harness the power of screenshots to be more productive