This is a Winterboard Battery Theme which uses the moon cycle to describe the battery charges. As the moon waxes and wanes so too... It's small, and off in the corner. So it is ideal for content rich lockscreens like Grupple... Seems to work fine, but is at version 0.5 because I haven't found 17 photos of the cycle between new and full. There's 15 and two extra "full"...
