Replace default mobile webapp logo icons

You can replace the default mobile webapp logo icons (themes/bootstrap_darkroom/img/logo.png) by using a custom plugin.

1. Upload you image somewhere in the Piwigo folder, the local/ subfolder is a good spot
2. In Administration -> Plugins -> LocalFiles Editor -> Personal Plugin add following between the <?php .. ?> tags:

add_event_handler('loc_begin_page_header', 'changeAppIconFilter' );
function changeAppIconFilter() {
 global $template;
 $template->set_prefilter('header', 'changeAppIcon');
}

function changeAppIcon($content, &$smarty) {
 $search = '#themes/bootstrap_darkroom/img/logo.png#';

 $replacement = 'local/mylogo.png';  /* <-- Set your logo path/name here */

 return preg_replace($search, $replacement, $content);
}

3. Enable the Personal Plugin in Plugin Manager