Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
Dingtone - Dingtone is a free call and texting application for making unlimited calls and text messages to any number at the moment registered in any part of the world by any cellular company.
TextMe - TextMe is a free calls and messaging application at both local and international levels.
Talkatone - Android App on. Google Play. Stop paying for cell minutes, texts & landlines; Turn your iPad or iPod touch into a phone; Call/Text even in areas with bad cell coverage; Call/Text when travelling without paying for expensive international minutes.
textPlus - textPlus lets you send and receive text messages without the need for a data plan.
Fongo - free VoIP app - free Canadian phone number