Description
TML – Tags for Media Library may be useful to anyone trying to use taxonomy tags on WordPress Media Library items. TML supports dynamically generating galleries using a criteria based on taxonomy tags, multiple tag taxonomies for media items, bulk assignment/removal of taxonomy tags to/from media items, filtering the Media Library by taxonomy tags, sorting the media items based on a priority tag, a search widget for media items using a criteria based on taxonomy tags and an alternate high density view of the Media Library. The website for this plugin is here. This version requires WordPress 4.6 and PHP 5.4.
A Multi-View Gallery Viewer
TML also includes a gallery viewer. TML’s gallery viewer is a plug compatible replacement for the standard WordPress gallery viewer for the WordPress

shortcode. It can be used independently of the other features of TML and supports five different views of a gallery.
Converting NextGEN Gallery 1.9 to WordPress Media Library
For NextGEN Gallery 1.9 users: This plugin first converts NextGEN Gallery’s image database to a WordPress Media Library image database. After the conversion NextGEN Gallery images and galleries have become WordPress Media Library images and galleries. A WordPress taxonomy ‘ngg_tag’ is created and the NextGEN Gallery image tags are saved in this taxonomy. This plugin implements the NextGEN Gallery shortcodes [nggtags], [nggallery], [slideshow], [album] and [singlepic] by dynamically translating them into an equivalent standard WordPress shortcode so post content with these shortcodes will still work without editing the post content. NextGEN Gallery’s sortorder is implemented using a tag taxonomy to hold priorities. This plugin works with NextGEN Gallery 1.9.13.