I'm looking for a free or low cost cross platform messenger app( Android and iOS) that is reliable, uses encryption, and also has the ability to receive messages on multiple devices at once. For example, I'm looking for a app that I can be signed into from my phone(OV) and my tablet(A100), and when someone sends me a message receive that message on both devices and have the ability to respond from either device. I do not want to use Facebook or G+. Any suggestions?