For all of you who love the flat look of OS X Yosemite, but don’t like Corona’s 3D icon anymore, this is for you.
Enjoy 
(Unzip attachment (just a zip around a .icns file) and copy over existing corona icon via “get info” contextual menu).
For those looking for the other custom icons seen in the screenshot, they are made by a guy called “Arn0” and are available to download here (Huge pack of custom Yosemite icons (for both first and third party apps, in various styles, rounded, square etc): https://mega.co.nz/#!JU0F0IpJ!XI03_uxre_69oiCZMEPRvQ8H4QD6_N2e2kWAdFadMbY
Disclaimer: Icon and it’s rights belong to Corona Labs. I just put a frame around it and made an icon file.