Jan 31, 2020 Update: UB Mega Menu v.1.1.8 release is fully compatible with Magento 2.3.4 and natively supports Magento PWA Studio.
Nov 4, 2019 Update: New enhancement in UB Mega Menu ver 1.1.7 -- allows to restrict access to specific menu groups to selected customer group(s). Fully compatible with Magento 2.3.3.
We’ve just released Magento 2 Mega Menu version 1.0.5 for Magento 2.1.8, which we think you are going to like. Technically, this update is not just a Magento compatibility release, it has been completely revamped throughout LESS/CSS code base. If you look back at the original code of the old version, you can see that, this update offers such advantages as easier and unlimited customization. The version 1.0.5 introduces an absolutely new default style and restructures all existing 4 styles much simpler. Overall optimizations are to make the extension run smoother with the latest Magento 2.
And you can try it right now here.
UB Mega Menu members, just head to your profile at Ubertheme to download the latest version 1.0.5 and follow our user guide here to keep you up-to-date on what changes we have applied to UB Mega Menu.
Below I’d run you through the new 5 default styles -- a very brief Before & After changes in the Magento storefront layouts:
New Default Style for Magento 2 Mega Menu

Absolutely new default style in UB Mega Menu 1.0.5
Style 1
Before:

Style 1 (UB Mega Menu v1.0.4 and older)
After:

New Style 1 (UB Mega Menu v1.0.5)
Style 2
Before:

Style 2 (UB Mega Menu v1.0.4 and older)
After:

New Style 2 (UB Mega Menu v1.0.5)
Style 3
Before:

One Column Layout (UB Mega Menu v1.0.4 and older)
After:

New One Column Layout (UB Mega Menu v1.0.5)
Style 4 (Vertical)
Before:

Vertical Menu (UB Mega Menu v1.0.4 and older)
After:

New Vertical Menu in UB Mega Menu v1.0.5

New Vertical Menu in UB Mega Menu v1.0.5 (cont)
(Backend Interface) Drag and drop functionality

Drag and Drop functionality remained unchanged
Will you try our Magento 2 UB Mega menu on your sites?
-- URL: http://megamenu.magento2.demo.ubertheme.com/
-- Username: megamenu
-- Password: megamenu@123