Don't iPhones and iPads also have a UNIX kernel?
Apple MacOS X is based on FreeBSD code (and lot of other code), and it certified as UNIX compatible, so MacOS X can be named as UNIX. iOS is based on MacOS X, so iOS is UNIX too.
The system as a whole is able to brand itself as UNIX compliant, though, because it complies with the Single UNIX Specification. That spec is concerned about userspace behavior, not kernel or implementation, and you don't have to include any actual UNIX source code to be able to brand your OS as a "UNIX" according to the spec and trademark guidelines.
BSD is a 'personality' layer.
Android phone's doesn't, as Linux is not technically a UNIX (doesn't derive from the original UNIX codebase in any way.
I don't think iOS is anything else than OS X with a different facade (Cocoa Touch, which for UNIX doesn't matter) and a few additional services. It has all the usual POSIX interfaces (and some of the userland) underneath. So even if it violates some models (e.g. with regards to user accounts), it's still the same codebase, heralding from the BSD years.