VCF Manager is a Simple Windows App for Managing Your Contacts
Over the years, Google has gotten better and better at organizing all of your contact information. You can easily add new contact info, update existing entries, and seamlessly sync your data between multiple devices.
This is all fine and dandy if you want to rely on the cloud, but if you’re looking for a quick and simple way to locally manage your contacts list, you might want to check out VCF Manager from XDA Junior Member 3llomi.
VCF Manager is an app for Windows that shows you all of your contacts in an easy-to-read grid view, compresses multiple VCF files so you can merge them all into a single one (and vise versa), and can also convert contacts2.db files to VCF ones.
3llomi does note that there’s currently a bug where duplicate contacts are made when doing the above file conversion, but this should be addressed in a future build.
Download VCF Manager from the XDA Forums