Try the new Pocket Developer Assistant!
The application allows you to create slicing icons in 2 clicks! Lots of platforms supported - just drag and drop icons and export slices for iOS, Android, OSX, WahthOS.
Also, there is a cheat sheet for the size of screenshots uploaded to the App Store Connect - now they are always at hand.
It should be added that the application has the ability to customize the design for a comfortable use of the application.
It's also worth reading the
privacy policy: https://sites.google.com/view/castles-trip-privacy-policy