Dead-simple, minimalistic PHP-based photo gallery for your files if you'd like to host them yourself, but still you would expect something decent.
http://aron.novaak.net/PHPGalleriaIO-Demo/
PHP 5.4.x or newer
Copy all the files in this repository to a directory that you'd like to turn into a web gallery. Or put images to this repository (and copy it to a server).
It scans all JPEG and PNG files in all subdirectories and puts into one flat gallery, sorted by the filename. The filename minus the extension is the caption that's visible for the photos.
See config.php for various configuration options.
Thanks for the amazing http://galleria.io/ that could make this little repo happen.