Since BlindSquare uses the GPS-capabilities of iOS-devices, you will benefit the most from using BlindSquare if you run it on an iPhone or an iPad that possesses a GPS receiver.
However, if you install BlindSquare on an iOS-device without GPS capabilities, for example an iPod Touch, you will still be able to hear information about your environment as long as you are connected to the internet.
This works, because your iPod can retrieve information about your approximate location using Apple’s database of wireless networks.