If you have an iPhone, you don't need a separate app to find an open wireless connection for your laptop.
Simply take out your iPhone, tap Settings, select WiFi, then open Choose a network to see which Wi-Fi networks are available wherever you are. Perfect for checking to see if it's worth hauling out and booting up your laptop in your local library or coffee shop, or for checking whether your home network is visible from that corner of the garage or basement where you're considering moving your desktop.
Want to find the nearest wireless access point wherever you are? Try searching for "wifi" in the Maps application. Google will plot the nearest hot spots around your location based on the GPS (or cell-phone tower location).