No need to worry about the duplicate contacts as it only saves the unique contacts while extracting the same to your phone.
The application is tested on all Major Devices and is compatible with the devices above android 2.1
Some Unique features of Backup My Contacts,
1. Fast and easy to use: Unlike other contact backup apps, the backup process in this app is very fast ( Backup is taken within mini seconds)
2. No Duplicacy: As the contacts are saved in XML format which saves only the unique contacts while the extracting the contacts on to the phone
3. Easy to Transfer: Contacts backup can be transferred through Bluetooth, Wifi, Email, Gmail, Dropbox and Etc
4. Delete Contacts: Delete all your contacts instantly in one go
5. Safety: As your Contacts are stored in XML format instead of a .VSF file no one except you can decode the file