Thunderbird Contact Sync.

TBird app synchronizes contacts between an iPhone (iPad) and the Thunderbird email client.
This app works in conjunction with a small MS-Windows application, which can be downloaded for free from www.abamberger.com - without any further costs. After installing this application on your PC, your contacts in Thunderbird can be integrated into your iPhone contacts. The TBird app supports creation and deletion of contact groups. This makes a well arranged contact list possible. Attention:Only unidirectional!