Are you already touching the Google+ limit of 5000 people in your circles? Do you want to do some clean up and get rid of all the inactive people? Uncircle+ is a Google Chrome extension for you.
Uncircle+ lets you uncircle people (i.e. remove) inactive people from your Google+ circle with ease. So, if you want to add new people to your circles, you can add them without reaching the 5000 limit.
Do note that the “Inactive people” here referred by the author of the extension, are those people in your circles who have not shared any posts (original, reshare, private or public posts) with you. So, if that person is having at least one post, he is active. Thus, after doing the housekeeping with this extension, if you want to further cleanup “dormant” accounts, you have to do so manually. We are referring “dormant” here are those people who have not shared any post for a long time after they signed up.