By using your Mac as a surveying tool, NetSpot Pro helps you to troubleshoot and optimize your Wi-Fi network. Right now, you can grab this OS X utility for $19 via 9to5Toys Specials.
With the app open on your Macbook, you can build a heatmap of signal strength around your home or place of work. This gives you a comprehensive view of the dead zones, meaning you can adjust the position of your router to improve the signal where it is needed. The app can also help you with choosing the best radio channel, seeing all the local networks that may be causing interference, identifying access points, troubleshooting network issues, and testing your upload and download speeds. All of the collected data can be exported in customizable reports, and you can keep running the tests to optimize your network(s).
This deal takes 87% off the price of the app, with minor updates included.