iOS Jetpack - Beautiful easy-to-use screenshot templates for App Store
Sticker List - Discover the best stickers daily and publish your own.
AppLaunchpad - Create free beautiful screenshots for App store/Google play
Sticker.Place API - Get stickers for your app
App Screenshot Maker - Design marketing screenshots for your app in minutes
Unixstickers by Sticker Mule - Stickers for fans of unix, software, coding and open source