Update: Deal over.
TP-Link N300 Wi-Fi Range Extender with Pass-Through Outlet – Link 
Amazon has this on sale for today only, for just $19.99!
This normally sells for $29.99 and is now its lowest ever.
- Extends your network’s Wi-Fi for reliable coverage in hard-to-reach areas
- Eliminate Wi-Fi dead zones throughout your home
- Extra power socket keeps your outlet free for other devices
- Two external antennas help boost Wi-Fi range
- Ethernet port helps connect wired devices such as a game console, smart TV, or streaming player to your Wi-Fi network
- Smart Signal Indicator Light helps you place the extender in the perfect spot
- Universal compatibility
- Industry-leading 2-year warranty and unlimited 24/7 technical support