Makeicon: Generate icons for mobile apps in a second (and get rid of manual work)
Generate mobile app icons in all resolutions for both iOS and Android.

I'm not going to talk about “How to design the best app icon ever” or “10 tips&tricks to create awesome icon”. Yes, the app icon is maybe the most important part of your application … but, the developer point of view is something different. You get the icon in hi-resolution and have to create dozens — let's say — “modifications” for each platform, each and every device, for a specific icon usage / placement (for iOS) etc …
makeicon
For this purpose, we've created simple CLI tool called “makeicon” that you can use to generate all required icon resolutions you may need. In a second.
You know it. As soon as you made all the necessary icons in their respective resolutions, the adjustment request will come in (because of colors, because of a small change as a result of testing etc.) and you can start right from the beginning. And sometimes repeadetly and all over again.
With makeicon — just provide square icon image with a minimal resolution of 1024px × 1024px and the rest will be created automatically for you. Currently, all existing resolutions are being generated — just use the ones you need.
It's available for all platforms, but you’re definitely using Mac 😜 as a mobile app developer, so there’s easy installation through Homebrew.
You can find the makeicon CLI tool here:
https://github.com/beplus/makeicon
Definitely, this is not the “one and only” tool available out there — right?! But whenever I needed to prepare the icons, I was not able to find the one that will do the right work for me. So we did our own and if it can help anybody else, I will be pleased.
I think it's still some kind of “work in progress” — if you have any suggestions on how to improve it, let me know or create a pull request.
Enjoy!
PS: Look at the Github Wiki page to see all resolutions as well as the corresponding description of each generated icon.

