Followers notification

[asas asasas]

Hey.

I want to ask, there is alot of channels that have some thing that if someone following them or subing them they have notification 

I want to ask is this widget or something with the API? please help me with that.

I don't know anything about the API.

Thank you,

Samuel

[Jeff Fisher]

I would also like to know this, I would GREATLY appreciate a response.

Thank you.