I just tested the Mobile Menu feature on a Droid smartphone, sorry I don't know what OS version or Browser version. (Whatever version it is plays nice with OM Maximenu.) It's about 18 months old.
I've made the development site live since it's nearly complete: http://naitauba.adidafoundation.org
The mobile menu toggle works fine for regular desktop browser, but not for the Android phone. Here's my experience:
The menu does become a single button, whether text or icon (I tested both). That's fine.
I can see that the link is active (it glows green).
But the menu does not drop down (whether text or icon). So effectively, the site is menu-less.
I'll be able to test it on an iPad tomorrow, and I'll see if I can get the Android info -- so more details will follow.