NetQin Mobile Guard or Anti-virus
There are plenty of cool, free and useful applications for Nokia smartphones but we should remember that any networked-enabled devices should be protected and maintained. The next two applications that you should consider installing provide the protection and system performance monitor or maintenance you will need, and even basic protection against the growing numbers of threats for mobile phones.
NetQin Mobile Anti-virus is a free virus scanner on Nokia phones. It features full scanner for Trojans, virus and other types of malware that target mobile platforms. Also, a network firewall protect adds extra protection in real-time. The paid edition of NetQin mobile antivirus includes Mobile Anti-lost, backing up of contacts, and anti-eavesdropping features. Download the free antivirus protection from http://www.netqin.com/en/antivirus/symbian/.
Free Mobile Guard by NetQin is another important application for Nokia. It checks the phone's memory using a System Optimization feature. Other features include Web Usage Manager, Proactive Protection against malware, and Spam Cleaner. You can download it from http://www.netqin.com/en/guard/symbian/.
Note: It's not recommended to run more than one antivirus program in any computer or phone. If you have NetQin Mobile Guard already, there's no need to install NetQin Mobile Anti-virus.