These are the changes I made to the standard minigal nano 0.3.5 .
http://www.minigal.dk/minigal-nano.html

- 20140817
Added the filename in title of the picture

- 20140817
Added the option to get a random firstimage picture for folder branding using a setting in config.php

$random_icon = "true";

I also modified the function in this simplier way:

function getfirstImage($dirname) {
        $imageName = false;
        $files = glob($_SERVER['DOCUMENT_ROOT']."$dirname/*.{jpg,JPG,jpeg,JPEG,png,PNG}", GLOB_BRACE);
        if ($random_icon = "true") {
                shuffle($files);
        }
        $imageName = basename($files[0]);
        return($imageName);
}

- 20140817
Added a CUSTOM key to show a footer.
If exist a .README file in a folder that file is shown as folder footer.

Modified the index.php:
[...]
                $template = preg_replace("/<% version %>/", "$version", $template);
                if (file_exists($_SERVER['DOCUMENT_ROOT']."$currentdir/.README")) {
                        $folder_footer = file_get_contents($_SERVER['DOCUMENT_ROOT']."$currentdir/.README", FILE_USE_INCLUDE_PATH);
                } else {
                        $folder_footer = "";
                }
                $template = preg_replace("/<% folder_footer %>/", "$folder_footer", $template);
[...]

in my custom template I used:

[...]
<div id="page_nav"><% page_navigation %></div>
<br />
<% folder_footer %>

- 20140824
Added a CUSTOM videos file that is parsed at the end like the .README one.

The .VIDEOS file contains the links to be included.

index.php in modified to reflect this:

                if (file_exists($_SERVER['DOCUMENT_ROOT']."$currentdir/.VIDEOS")) {

                        $videos =       "<strong>This gallery has some related videos:</strong><br>".
                                        file_get_contents($_SERVER['DOCUMENT_ROOT']."$currentdir/.VIDEOS", FILE_USE_INCLUDE_PATH);

                } else {

                        $videos = "";

                }

                [...]

                $template = preg_replace("/<% videos %>/", "$videos", $template);

the template is modified too for using the <% videos %> TAG.

- 20160210
Changed the thumb generator line 62 in:
$exif = @exif_read_data($_GET['filename']);

to prevent error in thumbs generators.

- 20160211

Switch to Lightbox
http://lokeshdhakar.com/projects/lightbox2/

Switch to http://fancyapps.com/fancybox because lightbox doesn't show video

- 20181223

Fixes for PHP 7.x
Update FancyBox to the latest v2
Fixed the random thumbnail.