The app shares your location with people you authorize, and it lets you see where they are on a map, too. It’s obviously an awesome way to track where everyone is for hanging out, and it’s also convenient to know when your friends will be arriving if you’re waiting for them somewhere. (Of course, this assumes that you trust your chums with that kind of information. The paranoid need not apply.)
One of the useful features in the app is the ability to select which device shares your location. Why is this important? Well, for starters, you can use it to be really sneaky. Let’s say you’re going Christmas shopping for your pal Timmy. Timmy has asked for a chainsaw from a particular hardware store, so if he happens to check your location while you’re out shopping, he’ll know what you’ve gotten for him. However, if you’re all stealthy and switch the device that’s being tracked to your at-home iPad instead of your iPhone, all Timmy’ll see is that you’re sitting at home. To me, that’s far less suspicious than “location not available,” which is what your followers will see if you actually toggle on “Hide My Location” instead.
And, I mean, I guess you could use this trick in more nefarious ways to really, truly hide awful things from people, but don’t do that, OK? I’ll be very disappointed in you, and you won’t deserve chocolate or coffee or any of the other best things in life.
Anyway, here’s how you do it. Open the Find My Friends app, and then touch the “Me” section at the bottom of your iPhone's screen.
(If you're on an iPad instead, touch the three-lined “list” button at the upper-left, tap “Me,” and then press the “i” next to your location to access your settings.)
Afterward, you’ll see all the options for how you share with your followers. Here’s where you’ll find the less-sneaky “Hide My Location” choice, but underneath that is “Share My Location From” followed by a list of your iOS devices.
Pick the device that's gonna stay where you want folks to think you are, and you're done! You sly dog, you.
Finally, note that these instructions are for the iOS 7 version of Find My Friends; if you’re using a previous version, check out this Apple support article on how to change which device you’re transmitting from on earlier versions of the app.