Hiya is a special app that allows Smartphone users to see who is calling before they answer the phone. This allows them to ignore calls from strangers and even trace the blocked or hidden numbers of phone pests, while the app also boasts plenty of other cool features. A real bonus is the fact that unlike many free apps of this type there is no unwanted advertising that pops up out of nowhere, which means that there is nothing to lose by taking Hiya out for a spin.