If you are willing to pay a dollar for an app to delete duplicate contacts on your iPhone or iPad, then Cleaner Pro is the best available. It has all the features you could ask for an app which deletes duplicate contacts. You can find all duplicate contacts and merge or delete them, remove or merge contacts with no name, phone or email and you can backup all of your contacts locally or email them to yourself.
You can sort duplicate contacts based on name, phone or email and merge them by selecting what you want for the merged contact. You can also merge or delete contacts on your Google, iCloud or exchange account. Just like Smart Merge, Cleaner Pro is also available in many languages.
Here were the best 5 apps to solve your duplicate contact issue. Hope you will be able to use one of these apps to delete duplicate contacts on your iPhone or iPad very easily. You will be able to scan all of your contacts and see all duplicate ones with duplicate contents inside of them.