You can conveniently sync your contacts between your iOS devices with iCloud. But if you want to export your contacts, the following contact app Export My Contacts should be more suitable for you.
Export My Contacts is a powerful contacts exporter developed by xiaoxiaoyu, and designed for iPhone and iPod touch. The iPhone app features reasonable and intuitive layout. All the four functions have be listed on the bottom of the interface including Groups, Export, Files and Settings. You can browse your contacts and edit them under Groups, while the Export tab allows you to export your contacts in various different formats including CSV, TSV, vCards and Excel for different platforms. Apart from that, the Settings tab also allows you to enable photo export function.
Export My Contacts with a size of 4.2 MB is compatible with iPhone, iPod touch and iPad running iOS 4.0 or later. The iPhone app is free for a limited time at present. If you’re interested, jump to App Store for more details.