Radix Icons - A crisp set of 15×15 icons. Open source.
App Icon Maker - Create icons for mobile app stores online for free.
MakeAppIcon - MakeAppIcon resizes and optimizes your icon designs into all formats needed for iOS and Android mobile app!
EasyAppIcon - EasyAppIcon helps you to create your own app icons easily. Supporting Android Adaptive Icon!
Bjango App Icon Templates - App icon templates for PS, Ai, Sketch and Affinity Designer
Flat Icon Generator - Create stylish, flat icons for Android apps.