M Launcher theme - Marshmallow supports with following launcher.

-> Apex Launcher
-> Adw Launcher
-> Nova Launcher
-> Smart Launcher
-> K-Lite Launcher
-> Aviate auncher

Marshmallow themes will beautify your launcher icons and make your phone phone beautifull with flat design.
Marshmallow theme also have unique material wallpaper that will help your desktop more trendy and unique.

How to install and apply marshmallow theme.

--> click on apply theme
--> install your favourite launcher listed above
--> click on launcher and apply
--> Done

Now you have marshmallow launcher theme with flat design icon pack.