If you want to improve user experience on smartphones then you might think about using the Photoswipe library. This enables swiping through the images (once you click on one to open the gallery), furthermore it preloads images so that when the user swipes to the next image it is already there. This makes him feel as if the photos were stored on his local device.
For Koken there already exists a plugin on github. Just download, unzip and load into the /storage/plugins folder of your Koken installation. Then enable it over the Koken admin page and that's it.
For more infos ab about the plugin please check here.