Raven is a free and open source android messenger for Facebook, SMS and E-Mail. It supports a true end-to-end device encryption and keeps the usability simple at the same time. Download: https://play.google.com/store/apps/details?id=com.urbapps.raven
#Cryptography Notice This distribution includes cryptographic software. The country in which you currently reside may have restrictions on the import, possession, use, and/or re-export to another country, of encryption software. BEFORE using any encryption software, please check your country's laws, regulations and policies concerning the import, possession, or use, and re-export of encryption software, to see if this is permitted. See http://www.wassenaar.org/ for more information.