This is the first I've heard of Copperhead. From their install page [1]:
"You can obtain the adb and fastboot tools from the Android SDK. Either install Android Studio or use the standalone SDK. Do not use distribution packages for adb and fastboot. Distribution packages are out-of-date and not compatible with the latest version of Android. An obsolete fastboot will result in corrupted installations and potentially bricked devices. Do not make the common mistake of assuming that everything will be fine and ignoring these instructions. Double check that the first fastboot in your PATH is indeed from an up-to-date SDK installation"
Great if it works for you, but this is clearly not a viable option for the great majority, nor is it an example of "polished UX."