gang, Here's a fun one. I'm trying to get a (regular ol')

Hey gang,

Here's a fun one. I'm trying to get a (regular ol') menu item to appear only on non-desktop viewports. I've tried a few different angles:

A separate theme and theme-switcher. For some reason (I'm using Twenty Fourteen here, and I've tried killing all plugins) it doesn't work.
If Menu and WP Mobile Detect. If Menu doesn't recognize WPMD's new functions.

I'm sure this can be done, and probably easily. Any ideas? Thanks!