Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
Talk360 - Talk360 is a best-in-class communication utility that offers a convenient way to connect with loved ones globally.
TextMe - TextMe is a free calls and messaging application at both local and international levels.
FluffyChat - Open. Nonprofit. Cute ?
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.
Textnow.com - It lets you text your friends, aka my only source of happiness