Google+ is offering a "Sign In Button" that can be used on 3rd party websites and apps to authenticate a user.
If you are interested on how to use this button in your project you should check the Google+ Developer Pages: https://developers.google.com/+/web/signin/
We would like to explain here the Sign In from the view of the user and describe the main points regarding your privacy and what kind of access you give the app.
1.) Give access to your circles while using the Google+ Sign In
General: In the Sign In popup/window of Google+ you can choose which circles you want to show to the 3rd party app. By choosing circles the app will be able to get a list of the persons/pages in this list but not the names of the circles or the number of circles a person/page is included. It is just a list of id's that are in at least one of the circles you have chosen.
CircleCount: You don't need to choose any circles here if you don't want to. The only features that are using these information on CircleCount are so far:
► the Map of your Circles (http://www.circlecount.com/mycirclesmap/)
► the birthday list (http://www.circlecount.com/mybirthdays/) and
► "Your Google+ Elements" (http://www.circlecount.com/myelements/)
But you have a button to update these information on the pages of these features, so that you can unselect all circles on your first Sign In and check out CircleCount without showing us any of your circles. It's your choice!
2.) Allow people to know you use this app
General/CircleCount: Here you can choose the visibility of the app / CircleCount on your profile page. You can see the full list of apps you have signed in to with Google+ on this page https://plus.google.com/apps where you can also change the visibility or disconnect from this app.
3.) General Sign In
CircleCount: On CircleCount we are using the Google+ Sign In to replace a user registration. You don't need to create a CircleCount profile, you have it as soon as you have a Google+ profile.
With the Sign In you are telling us who you are, so that we can show you
► your dashboard (http://www.circlecount.com/dashboard/)
► your follower map (http://www.circlecount.com/mymap/)
► your favorite posts (http://www.circlecount.com/favposts/)
► your custom ranking using the criteria you define (http://www.circlecount.com/myranking/) and
► many more features that are available with a free Sign In
There is no official / publicly available Google+ API that allows apps to post in your name.
There are the interactive posts (http://goo.gl/0v9yZ7) which can be used within an app as a button. You will have to click this button and choose the circles/persons you want to share an interactive post with. Default setting is that the post will be private.
You can find such interactive posts on CircleCount
► on our A vs. B pages (http://beamto.net/26v8tcaz/)
► on your follower map (http://www.circlecount.com/mymap/)
► on our polls (http://www.circlecount.com/poll/2)
There are also the app activities (http://goo.gl/je4L76) which can be generated automatically by the app without that the user has to do anything. These app activities can be found here (https://plus.google.com/apps/activities) and can be shared, but you still need to go to this page and choose an app activity to share it publicly or with your circles.
CircleCount is generating such entries when
► you sign in, so that you can get a good overview of when you have logged in on CircleCount
► you add a tag to a person/page (here is the complete list of tags on CircleCount: http://www.circlecount.com/addtag/)
If you have any questions please comment on this post. We will try to answer them and update the post.
This post is based on a question of (http://goo.gl/2sIdNr) in the Communitiy of (http://goo.gl/odt40K). Thanks also to and
#googleplus #signin #interactiveposts #appactivities