iStumbler is a utility for finding wireless networks and devices with AirPort or Bluetooth-enabled Macintosh computers.

[1][2][3] iStumbler was originally based on MacStumbler source code.

[citation needed] Its early development focused on detection of open wireless (802.11) networks,[citation needed] but more recent versions support the detection of Bluetooth wireless devices and Bonjour network services.

[5] It was later changed to nagware, having a pop-up screen every 30 minutes but otherwise being fully functional.

[1] It uses GPS data to display the coordinates of the computer being used and nearby Wi-Fi points.