I’m thinking about switching to an Ubuntu phone if the next two iPhones don’t have headphone jacks. If I do this, I’ll need to use a different IM app than iMessage. However, most of the IM apps I’m tried have to be open to be able to receive messages. I’m looking for an IM client which meets these criteria: 1. Available on iOS, Mac OS X, and Ubuntu Touch 2. Encrypts messages 3. Can receive messages when closed, possibly through the use of a daemon.