In an effort to compete with Facebook, which recently closed its acquisition deal with photo app Instagram, Google picked up its own photo app--an Instagram rival called Snapseed.

According to Reuters, Google acquired Nik Software (the company behind Snapseed) for an undisclosed amount on Monday. The news came in tandem with the announcement that Google+ had reached 400 million sign-ups with 100 million people defined as "active users."

“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,” Google’s Senior Vice President of Engineering wrote on his Google+ page. “While Google+ is all about creating a better experience across Google, it’s also a destination.” 

Google is betting that destination will be even more attractive with compelling photos. Snapseed won the 2012 Best Mobile Photo App award from the Technical Image Press Association and also Apple's iPad App of the Year. While the app is more focused on photo editing than Instagram, Snapseed also lets users share images via social networks. Another big difference: It's not free. Unlike its counterpart, Snapseed is $4.99 in the iOS App Store. A $19.99 desktop version for Macs and PCs is also available.

"We've always aspired to share our passion for photography with everyone, and with Google's support we hope to be able to help many millions more people create awesome pictures," Nik Software said on its site.