Delay Rated 4 out of 5 stars
Might be just me, but there is a short delay from when "New Tab" is opened and the custom background is displayed.
With the delay, the custom background is only displayed for a slight second before I click a thumbnail. Which pretty much makes this add-on useless.
Nevertheless, good work. And hope you continue to develop since there are no built in ways to customize the "New Tab" page