After testing all these applications, we can classify them into three things: backup speed, compatibility, and interface.
At the backup speed, McBackup was the fastest of all other applications because it was backed up offline and did not need to be connected to the internet to be able to perform the backup. The longest backup application was iDrive Lite.
As far as compatibility is concerned, McBackup once again fared better than other applications because the backup made creates a universal format (.vcf) file where the vast majority of operating systems and applications can read. But it is also worth commenting that has a Windows Mobile has the ideal application is Plaxo Address Book Backup and who has Nokia Contact Sync has this compatibility.
In terms of interface, McBackup and iDrive Lite applications were the most intuitive and easy to perform their functions.
In short, the best app for backing up your contacts is McBackup.