Cell Phone Locator is a novelty app that supposedly allows you to type a phone number into it and then it displays the location of the associated phone on a map. It is a free app that installs easily.
When you launch Cell Phone Locator it displays a text box for you to enter a telephone number. Then you select the type of map you want, click the Track button, and the location of the phone number shows up on the map. What the app really does is display the location of your phone, on the assumption the person you are trying to fool into thinking you can track them is right next to you. The number you type into the app belongs to the person's phone, which ostensibly is also next to you. Since you can't really track the phone, this ruse only works when the phone and the person who owns it are next to you.
The problem with Cell Phone Locator is it doesn't really do anything, and many phone users are now smart enough to realize you can't actually track them, so the amusement value of the app is limited. Still, it can be a good gag. Once.