Google+ sign-in was announced a short while back. You have likely seen a few examples of this on sites, however for those who may have missed it, Google+ sign-in is not all that different from what we have seen with Facebook and Twitter. That is to say, you can use Google+ to sign into an app or service. This generally makes the sign-up process easier as it takes details from your Google account.
One of those who happen to allow for Google+ sign-ins is TuneIn Radio. That bit aside though, because it looks like we may soon be seeing quite a few more of the Google+ sign-in options around the web. Basically, two of the big players have recently integrated Google+ sign-ins. These two companies are Janrain and Gigya, which according to Google, have "hundreds of thousands of developers" already using their services.
Granted, this does not necessarily mean that these hundreds of thousands will all instantly begin using Google+ sign-in, however it does give the extra possibility that they will. Some of the sites that have already begun using Google+ sign-in as a result include NPR, Universal Music Group sites to include ladygaga.com, justinbiebermusic.com, imaginedragonsmusic.com, eminem.com and interscope.com as well as HSN from Janrain and American Idol and Food Network UK from Gigya.
In addition to having this mean an easier account set-up process, there are also some other benefits for the end user such as having a more interactive experience thanks to the sharing. There will also, in some cases, be the ability to download and install the Android app (at the same time as you are signing up for the service using a regular computer). Not to mention, there is also the bit about already having a trusted account with Google. Now we just have to see how many users actually choose to sign up with Google+ as opposed to Facebook or Twitter.
[via Google+ Developers Blog]