One of Android's most powerful features is its Share menu. At its core, the Share menu simplifies sharing something from one app with another. A photo in the Gallery app can easily be shared using Google+ or Twitter, simply by choosing the Share menu and selecting the right app.
Developers can add their own apps to the Share menu, using something called "Intents". There is no need to wait for an OS update; virtually any app can integrate itself into the Android sharing system.
This tag is to be used for questions regarding the Share menu.