The Israeli facial recognition technology company producing the App at Face.com has been acquired by Facebook, following the $1 Billion acquisition of Instagram, showing a clear move for the social network into the world of Mobile.

The cost isn’t public knowledge at this time, but TechCrunch has the following:

We’ve heard from multiple sources that the acquisition price was around $100m, with others reporting that the price was between $80m-$100m. (Update: We’re now hearing from a source familiar with the matter that the price was between $55 and $60 million, and that it was a mix of cash and stock. The exact value of the deal will be changing depending on the price of Facebook’s stock.) This is absolutely not an acqui-hire, as Facebook will be taking full advantage of the company’s technology and the advancements it’s made on mobile — perhaps to finally include mobile tagging options for photos.

As Face.com’s speciality is mobile facial recogition, it could potentially allow you to upload a photo to Facebook while on the go, instantly receive suggestions of whom to tag, and confirm the tags with one click.

This is important to Facebook because right now there’s probably a ton of untagged mobile photos getting posted. Those are lost opportunities for engagement because when you get notified that you’ve been tagged in a photo, you probably visit Facebook immediately to check it. These tags also help Facebook understand who a photo is relevant to, so it can feature it in the news feeds of your closest friends.

The Official announcement from face.com:

Facebook has acquired Face.com! Our mission is and has always been to find new and exciting ways to make face recognition a fun, engaging part of people’s lives, and incorporate remarkable technology into everyday consumer products. If you’re anything like us, Facebook is a part of your life every single day. We keep up with our friends and family, share interesting (or mundane) experiences from our daily lives, and perhaps most importantly for us, we share a LOT of photos.

We love building products, and like our friends at Facebook, we think that mobile is a critical part of people’s lives as they both create and consume content, and share contentwith their social graph. By working with Facebook directly, and joining their team, we’ll have more opportunities to build amazing products that will be employed by consumers – that’s all we’ve ever wanted to do.

Now, lots of developers use Face.com technology to power various apps and make wonderful products. We love you guys, and the plan is to continue to support our developer community. If there are new developments you can expect to hear from us here, on the developer blog, and through our developer newsletter.

Thank you to all of our supporters, our amazing dev community, to our employees and to our friends and family who have seen us through many long days and longer nights. The next steps are going to be exciting for all of us.

– Gil and the Face.com team