It turns out that inline !important rules cannot be overridden -- grr! So you say that footer was created using a plugin? Do you happen to know which one?
What you can do is hide that custom footer for cell phones using a media query in your CSS:
@media screen and (max-width: 600px) {
#wp_footer_menu {
display: none;
}
}
You should also add a display:none; to the #FollowMeBubble that was discussed in an earlier post. As I mentioned previously, the visibility is already set to hidden, but the element still takes up space. Setting the display to none will remove the space that it's taking up.