Wannathis - 3d illustrations and freebies
App Store Inspiration - Best iOS App icons, screenshots, landing pages & heatmaps
Craftwork - A collection of User Interface resources made by Craftwork
App Icon Template - Royalty free app icon creator for iOS, OS X and Android
Icon Rewind - Get old app icons for your phone
Bjango App Icon Templates - App icon templates for PS, Ai, Sketch and Affinity Designer