AP Grapher is a freeware program for Mac OS X which searches for and displays nearby wireless (AirPort/WiFi) access points along with information about their percent availability, maximum signal strength, and last contact time. The grapher window allows you to graph multiple signal strength parameters for the base station you are currently connected to and optionally display them in the dock icon. Many user configurable preferences allow you to customize its behavior including refresh rate and optional display in the dock icon or menu extra.

AP Grapher is intended to help you find the best wireless access point to connect to and optimally position your base station and or computer to achieve the best possible signal strength. Note that the stumbler is not capable of finding intentionally hidden networks - it will only locate networks broadcasting their SSID (same as the default Airport menu on your Mac).