If This Then That (IFTTT) is a web application that connects the APIs of multiple popular web applications to allow actions to be taken on a destination site when an event occurs on a source site.
More info at IFTTT's WTF page.
Combine Channels together to make recipes that execute tasks for you.
More than 60 channels available to make thousands of different combinations.
Add a channel, add another channel, create a recipe, and you have a task. It's like witchcraft for the web without the eye of newt (unless that becomes a service).
Tasks are executed every 15 minutes to do what you want. There is a list of recipes available for you to get started.