If This Then That (IFTTT)
IF This Then That — or IFTTT — is a free online service that allows users to connect together various web services and connected devices. Users integrate services by selecting a "channel" and creating a "recipe". Channels are available for a large set of services and devices including Facebook, Gmail, SMS, Twitter, Dropbox, WeMo, Google Glass, Foursquare, Evernote and many more.
By creating a recipe, users can perform various tasks like adding Instagram photos to Dropbox automatically, keeping a list of Foursquare check-ins in Evernote, or sending a new RSS item to Gmail. Even more control can be had for things like WeMo or Google Glass, where items can trigger specific functions on the respective device.
IFTTT is mainly web-based, but both an iOS and Android app are available as well.