Signal is a very interesting application made by planetbeing, the Dev Team member who worked on almost all decoding solutions for the iPhone, which displays information about the GSM signal. Signal records data from the phone's baseband chip and provides you with information about its power, plus other technical information about GSM towers in your vicinity. However, the Signal application has a very interesting feature, namely it displays on the map (in the Maps application, using GPS) all the GSM towers in your vicinity, including the one to which you are connected.
The application is very interesting, especially for those who use such information for purposes other than purely informative. Signal costs $4.99 and can be purchased from Cydia.
