Re: Now how do I add my old Blackberry 10 contacts to my new iphone 6 s plus?
What format did you copy them to drop box in? Is it a csv or some other format that can be read. If you still have the BlackBerry desktop software you should be able to sync the contacts to your desktop then copy them to iCloud or if you use Gmail or some other email app that syncs.
Here is also a nice article on Macworld.co.uk about ways to do this as well Transfer contacts from any BlackBerry to any iPhone - How to - Macworld UK
I recently moved my contacts, calendar off of Gmail to iCloud, as a MAC user I just had to d/l my calendar and import, contacts I just copied them over and email well I put my mail on forward from Gmail, its just easier than getting people to actually change my address.