One of the more impressive features of Google+ is the Hangouts feature. It enables video chatting among multiple friends at once over the Google+ platform, but organizations also use it to meet one-on-one with people. Googlers do it all the time to interact with developers. President Obama even joined in on a Hangout that may have won an out of work man a job.
With Hangouts providing a platform for all these kinds of events, it was pretty big news when Google released a Hangouts API preview a few months back. It's fantastic news then that the Hangouts API is now out of preview and available to the entirety of the development community.
Now developers of all sizes will be able to create Hangout apps. The good news is that Hangout app building should be recognizable to people who build web apps as it is essentially just that. Google describes it as just "a big window inside the Hangout UI." The features available to Hangout features now include:
Initiate a group video chat with up to 10 people
Control hangout microphones, cameras, speakers and volume levels
Add sound effects and attach image overlays to faces
Set UI elements such as the video feed, chat pane, and notifications
Once you get your Hangout app published, you can use the new Hangout button to direct people to it from your Web site. This should be especially handy for organizations or groups who hold frequent Hangouts.
If you want to get cracking at new apps right now, check out the documentation for it. Hangouts is definitely one of the coolest things to come out of Google+, so I'm sure there will be some equally cool Hangout apps being created over the next few months.