If This Then That (IFTTT) is a web-based automation service that customizes your computing experience. For example, if you want to receive a text whenever you get tagged in a Facebook photo, just tell IFTTT and it will notify you in real-time. It can perform a ton of different actions based on your needs and the list of websites and services it interacts with continues to expand.
Yesterday, IFTTT announced a free app for the iPhone that works in much the same way. If you add a photo on Instagram, you can ask IFTTT to instantly send the new image to your Dropbox. How easy is that? It's kind of like an Excel equation, although way more exciting — you build a command (which IFTTT calls a recipe) and, unless you tell the app otherwise, it will continue to carry out the action you requested.
This seems like a great way to take care of something a bit tedious without having to do much yourself. And in future versions of the IFTTT app, you'll be able to share your recipes with others to make their lives a bit easier, too.