LostGeometry.xyz - Huge set of 91 abstract 3D objects in various styles.
MakeAppIcon - MakeAppIcon resizes and optimizes your icon designs into all formats needed for iOS and Android mobile app!
Womp - 3D Made Easy
EasyAppIcon - EasyAppIcon helps you to create your own app icons easily. Supporting Android Adaptive Icon!
Spline - Design tool for 3d web experiences
App Icon Maker - Create icons for mobile app stores online for free.