Google says that it has 100 million active users among the 400 million that have signed up for the social network that celebrated its first birthday in June.

The positive numbers from Google echo a late July report from comScore, which noted that worldwide, the number of Google+ visitors jumped from 66.7 million to 110.7 million between November 2011 and June this year.

During the same time in the US, comScore said the number of Google+ users rose by 82%, from 15.2 million to 27.7 million.

Of course, Google+ remains far from the heights of Facebook, which claims some 950 million users, but it's a healthy place for Google to be, analysts say.

"It was only a year ago that we opened public sign-up, and we couldn't have imagined that so many people would join in just 12 months," said Vic Gundotra, Google's senior vice president of engineering. "While Google+ is all about creating a better experience across Google, it's also a destination."

Gundotra also announced in his post that Google has acquired Nik Software, a company largely known for the popular Instagram-like photo editing app called Snapseed.

The acquisition comes on the heels of Facebook's purchase of Instagram, another wildly popular photo app.

Google obviously didn't want to be left out of the photo sharing craze so now the two social networks having dueling photo apps, analysts said.

Zeus Kerravala, an analyst with ZK Research, said an acquisition like Nik Software can only be a boost as Google gains ground in the social networking business.

"This is a move to combat what Facebook did," Kerravala said. "Obviously, we live in a visually oriented society so its almost a must-have. Making it easier to add photos is a capability that is table stakes today. It fixes a big hole in Google+."

While Ezra Gottheil, an analyst with Technology Business Research, said Google+ is far from in trouble, it's not living up to some of the initial expectations.

"There's fresh content, so it's not a problem but I don't think it's very active," he said. "It's not dead but it's not taking on Facebook. It's not doing as well as they expected. It's not doing as well as I expected."

Gottheil, though, was quick to add that as long as the social network is alive and kicking, it can adapt and from that build momentum.