It offers users a record of their Watt usage at a glance and also stores how much energy has been consumed that day.
The Onzo even allows consumers to upload their energy usage to a website so that they can monitor their consumption over longer time periods.
Another energy monitor called the Wattson was released earlier this year.
It also provides users with real-time energy consumption statistics and, according to technology review website cnet.com, it "can start to plot your electricity usage by connecting your device to a PC or Mac with the supplied mini-USB cable".
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