Is the sharing interface in many stock iOS7 apps built in, or custom?

Question

As the title says, I wanted to know about the sharing interface that you see in Safari or Photos. Is it custom?

If it is built-in instead, what is it officially called so I can look up the Apple documentation on it.

For reference, this is what I am referring to (in this case from Safari):

Answer 1

Sounds like you need to get well acquainted with UIActivityViewController and what you can do with it.

There's also a sample project and NSChat transcript that you can find on my github.