TextNow
TextNow is a free iOS app that includes free texting, picture messaging, calling, and voicemail. This means you'll be able to turn your iPod or iPad into a phone for no charge. Texts and pictures messages are uncapped and allow an unlimited amount for no cost to you. With TextNow, you are give a dedicated phone number that you can give to friends or family whom they can reach you at anytime. Additional features include Bluetooth support, customizable voicemail greetings, customizable wallpapers, and the ability to add a signature to your text message. TextNow is ad supported to make up for the free cost, but you can upgrade to the paid version and remove the ads for fairly cheap.