I have installed Group apps and followed the online instructions. Group apps has not deleted multiple contacts in the built in iPhone 5 contacts list. It has only deleted contacts in Group apps contact list. Any suggestions?
There's apps that do this. Enter "Multiple Contacts Delete" in the search bar of the iTunes Store. Here's one:
Multiple contacts delete by socioapps https://appsto.re/us/safgM.i
Never used this app, so...