Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...

Easy Message - Easy Message app comes up with features to help users in effortlessly sending text messages to a phone number, which is not in the contact list.

TextMe - TextMe is a free calls and messaging application at both local and international levels.

Seecrypt - Seecrypt app allows users to do secure voice and conference calls by using advanced encryption features so they can contact their friends, colleagues, and family members without any privacy issues.

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.

Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.