There have been a few. The best is probably
Phatware dbExplorer. Does rock solid database backup/restore as well, selective or entire. I like that I can, for instance, tap Ctrl on a keyboard (SIP is fine), select Contacts, Categories, Appointments, then generate an auto-backup script for easy future backups of just these in a couple of taps. Cool software.
Another tool was from
TascalSoft. Sorry, I forget the name.
You can also copy all contacts, or any sub-category listed, by a Select All, Copy, Paste into a Pocket Word window. Not CSV, more of a 'book' view. Nice if you'd like to print them out. But DON'T use a CtrlX or Cut command in any way, as without a backup that can be bad.