This app can change the icons of the Google's launchers: Google Now and Nexus launcher

• Android 4.1.1 +
• Root
• Google Now Launcher or Nexus Launcher installed
• At least one icon pack

1. Open app
2. Select launcher that you want to customize
3. Grant SU access
4. Click an app that you want to change icon
5. Select suggested icon or pick one from an icon pack
6. Go back and click the "✔" button

Launcher will restart