A groundbreaking world first for Symbian handsets is the introduction of pop-up notifications, notifying users of incoming chats and events, while the application runs in the background.

Further significant additions to the Symbian update include kinetic scrolling for 5th edition touch screen phones, new chat screen and contact list layout, chat history, plus a direct link to the NimbuzzOut rate calculator for international calls have also been added.

Available as a free download from Symbian app stores, such as Nokia’s Ovi Store, and from www.nimbuzz.com, the new Nimbuzz for Symbian is unique in offering a centralised messaging client with the most comprehensive all-in one feature set – VoIP calls, Instant Messaging and file-sharing with the world’s most popular social networks, plus presence, profiles, location and now Twitter – making it the ‘must have’ application for Symbian users.

The Symbian release comes at a time of phenomenal growth for Nimbuzz; having passed the 13 million registration milestone last month, Nimbuzz now enjoys a current growth rate of over a million new registrations each month (that’s a new Nimbuzz user every 3 seconds!), an active user base of over 30% and an international user footprint of 220 countries, covering every corner of the globe.

Evert-Jaap Lugt, founder & CEO of Nimbuzz commented: “We are delighted to announce the integration of Twitter with our new Symbian client. Nimbuzz for Symbian is by far our most sophisticated client and the only product available to offer users such a comprehensive range of features and such a complete communications experience on one.”

Concerning its American expansion, Nimbuzz is seeking to capitalize on the immense opportunity represented by the US market which is said to account for 280 million mobile subscribers. And given the company’s fast growing user base in the United States, the expansion sounds like the right thing to do.

Just to set things straight, Nimbuzz is growing at well over 1 million new users per month, serving more than 200 million VoIP calls per week. Their mobile VoIP and social messaging products have seen quite a few stability and performance enhancements, making Nimbuzz the number 1 app on the GetJar USA app store.

“Nimbuzz has been very warmly welcomed by Silicon Valley and by a huge number of users in the USA. We’re excited by the US opportunity for a number of reasons. Firstly, we will be better able to support and respond to the needs of our growing user base in the US with local representation. Secondly, Nimbuzz will be well positioned to take advantage of the unrivalled business development, media and networking opportunities which exist here,” said vice president Tobias Kemper.

Together, the USA and UK offices will join Nimbuzz’ growing international network comprising headquarters in Rotterdam, offices in India, Argentina, Brazil, Europe, the Middle East, South Africa and Asia.

It comes with a smart buddy list layout which displays the avatar and presence information in one in combination with community and resource information.

Another great feature is a time sensitive user interface where a light touch will open your buddy’s profile and a stronger touch will instantly begin a new chat.

There are home screen notifications which make you aware of any activities (incoming chats for instance) while Nimbuzz runs in the background. Just in case you wish to switch between 2G, 3G and WiFi networks, there is an auto-reconnect feature that makes things easier for you.

Since the Android users are getting a chance to use Nimbuzz for the very first time they get a unique opportunity where only Nimbuzz integrates Skype IM and local social networks such as Hyves in the Netherlands.

Looks like a nice thing to play with, eh? It’s free to download at the Android Marketplace.

Full press release after the jump

Today, Nimbuzz announces the launch of its multi community mobile social messenger application for Android handsets. Unique for Android users, Nimbuzz introduces a revolutionary buddy list layout, Skype IM, a time-sensitive user interface, home-screen notifications, auto-reconnect, clickable URLs, and local social network support to make Nimbuzz the most sophisticated IM application for Android handsets.

Nimbuzz takes full advantage of the benefits of the Android platform technologies. Alongside home-screen notifications that alert the user on the home screen of activities such as incoming chats while the application runs in the background, Nimbuzz also added a time-sensitive user interface option that detects how long the user presses on a contact in the buddy list. A fast-click instantly opens the contacts profile; a long-click opens a live chat window.

These updates work alongside the auto-reconnect feature guaranteeing seamless connectivity, by instantly reconnecting whenever a connection is lost. The smart buddy list displays information in an intelligent way, combining avatar and presence information in one, with community icon and resource information, if the person is online on the mobile or PC, in the same line.

Integrating Skype IM is unique to Nimbuzz, which already supports multiple communities including Facebook, Google Talk, Yahoo! Messenger, Windows Live Messenger, ICQ and many more. Clickable URLs that make for a multi media chat experience, and the additional support for local social networks such as StudiVZ, Hyves, Gadu Gadu, and Giovani, add to the extensive feature list making Nimbuzz Android the most comprehensive mobile social messaging application available for Android handsets.

Evert-Jaap Lugt, founder and CEO of Nimbuzz said: “Mobiles are no longer just about hardware but software. Nimbuzz increases the value of the handset and enriches the user experience. Our Android version is a perfect example of what we do best, integrating Nimbuzz’s award winning service to bring the best out of each operating system and handset.”

Nimbuzz welcomes Android users to its community that grows at nearly 1 million new users per month and has recently been recognized as “Best Mobile Startup” by Techcrunch Europe, and Top Global 250 tech company by AlwaysOn Stanford Summit.

The free app is available to download from the Android Marketplace.