iOS: When you share a photo to a social network, you're also sharing your metadata, which typically includes your location. A clever person can easily figure out where you are with that data. Metapho is an iPhone app that gets rid of it before you share.
At its core, Metapho displays all your photo's metadata for you and offers a quick way to remove that data before you share it. What's better is the new iOS share sheet that makes it easy to remove that data when you're sharing a photo from any application. Just tap the share button, tap the Metapho icon, and you share your photo with the metadata stripped out. Metapho is technically a free download, but you'll need to pay $2.49 to unlock the ability to actually remove metadata.
Metapho (free/$2.49) [iTunes App Store]