We just tested and all works fine. There is no any issue on android mobile devices.

Just two tips.

• Change the #12 color (forum primary color) to your theme primary color : #3498DB
• Put this CSS code in Custom CSS Code area to make forum wider on mobile devices (delete all caches and test using private session to see the change):

@media screen and (min-width: 600px) {
    #wpforo #wpforo-wrap {
         padding: 10px 0px;
    }
}

The difference will be on screens smaller than 600px (on all mobile devices)

Some are still having problems and I can't figure out..  Does this mean anything to you?

ReferenceError: Can't find variable: tinyMCE (anonymous function) -- Ajax.js:198