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.
FluffyChat - Open. Nonprofit. Cute ?
Textnow.com - It lets you text your friends, aka my only source of happiness
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
Molly (Signal fork) - Molly is an independent Signal fork for Android
TeleGuard - TeleGuard is a secure messenger that makes it store that your data or chats are not stored while collaborating or communicating with partners and friends.