For Android phones you need to get the app called Conversations, and for Linux Windows Mac desktops you need to get the app called Gajim, and just enable OMEMO

For Android phones you need to get the app called Conversations, and for Linux Windows Mac desktops you need to get the app called Gajim, and just enable OMEMO encryption under plugins. Conversations for Android is definitely the best XMPP client out there right now, so just make all your family and friends use it. And everything will be transparently flawless.