Have you ever struggled with the tiny pop-up list in the UV/Image Editor? So have I!
Therefore, I made an addon that enables to pop-up an extra image list with specified number of rows and columns. Optionally, you can display all images in a plain list.
Moreover, the addon contains a button to clear all users for the selected image datablock. So, the image datablock can disappear after save and reload of the blend file and you can easily get rid of unwanted image datablocks.
UPDATE: I made also a similar addon to display materials (Extra Material List).
You can visit my blog for my addons: https://meshlogic.github.io/pages/blender-addons/
or blenderartists.org: https://blenderartists.org/forum/showthread.php?417628