Wait, are you talking about Sensorly or SignalCheck? Sensorly is the app that maps data connections so people can get a feel for how the network has been built in a city, while SignalCheck tells you about the signal strength and connection type. If you're looking for the latter read the first post in this thread or read this:
http://www.brianklug.org/2012/09/how-to-switch-from-bars-to-numerical-signal-level-on-ios-without-jailbreaking/