The Cell Ranger has nothing to do with the Lone Ranger in a jail cell, though if that happened he would in fact be that cell’s ranger. It’s a cell phone booster, like this one. It plugs into your computer through the USB port and then, with an on-board microprocessor filtering out unnecessary signals, it amplifies the signals that your cell phone actually needs.
The end result is a few extra bars of reception. If you need better reception, this should be near the top on your list of cool stuff to buy.