BatteryWorks 1.2.1 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This Mac app is an intellectual property of Exploding Orange. We recommend checking the downloaded files with any free antivirus.
From the developer:
BatteryWorks is a fun app which displays the level of your computer's battery. It does this by displaying a graph/thermometer or colouring an area of your screen a particular colour to show you the battery level. These can be on your menubar or desktop.
The size and location of the graph can be selected. The colour (and transparency) of both when the battery is empty and when it is full can be specified.