What are some alternatives?
IconStore - Free icon packs by first-class designers
AppIconizer - Icon generator for App Store & Play Store submissions.
App Icon Generator - Generate your app icons in milliseconds!
EasyAppIcon - EasyAppIcon helps you to create your own app icons easily. Supporting Android Adaptive Icon!
IconBros - Free and continuously growing high quality icons
Appicon - Generate app icons and AppStore screenshots with just one click.