Tuenti is the new kid on the mobile social networking space. A Spanish social network with 13 million users, Tuenti is like a simplified version of Facebook and Twitter. And now it has decided to go global and add some new features.

Tuenti, acquired by Telefonica in 2010, will be launching an integrated mobile messaging app as well as the beta versions of Tuenti apps for Android and BlackBerry devices. iOS and Windows Phone apps will follow soon.

What exactly is Tuenti? Its basic concept is “social done simple,” with three basic options: broadcasting messages to everyone, to your close friends, or just directly to single contacts. Tuenti’s messages are limited to 140 characters like in Twitter and you can post status and photos called “moments”, that subsequently appear in your friends’ timelines.

Here’s an insight into the name Tuenti. In Spanish, it’s “tu entidad”, meaning ‘your entity, your identity’, and in English it’s a pun on the number 20. The idea is that most people  regularly chat only with 20 friends or less, with 90 percent of messages actually only sent to the same few friends. In Tuenti, your 20 friends become your default network.

Telefonica wants to bridge some of its more legacy features into some of its newer platforms: The messaging option on Tuenti that allows people to chat in real time, is also coming online along with other features.

Tuenti is also about privacy and security, which may not work smooth if it starts making money through advertising. Sign-ups are done using people’s real names, requiring them to enter a mobile number to verify their accounts. It sends data via SSL, so none of the activity on Tuenti is ever indexed in Google.