\documentclass{article}
\usepackage{ulem}
\pagestyle{headings}
\begin{document}
To make the mode "Dynamic" at the login screen you need to edit the ./imp/login.php file.  Search for the code that looks like this:

\begin{verbatim}
 
/* If DIMP/MIMP are available, show selection of alternate views. */

$views = array();
if (!empty($conf['user']['select_view'])) {
    $apps = $registry->listApps(null, true);
    if (isset($apps['dimp']) || isset($apps['mimp'])) {
        $views[] = array('sel' => false, 'val' => 'imp', 'name' => _("Traditional"));
        if (isset($apps['dimp'])) {
            $views[] = array('sel' => true, 'val' => 'dimp', 'name' => _("Dynamic"));
        }
        if (isset($apps['mimp'])) {
            $views[] = array('sel' => false, 'val' => 'mimp', 'name' => _("Minimalist"));
        }
    }
}
\end{verbatim}

Set the value for "Dynamic" to true as in the example above

Alternately, in order to not override mobile phone detection, change:\newline
\begin{verbatim}

        : ($browser->isMobile() && isset($apps['mimp']) ? 'mimp' : 'imp');
\end{verbatim}

To:\newline
\begin{verbatim}

        : ($browser->isMobile() && isset($apps['mimp']) ? 'mimp' : 'dimp');
\end{verbatim}

\end{document}
