While on the surface WhatsApp remains the king of the messaging hill, beneath the surface there are some worrying signs for Facebook’s flagship platform. With its 2 billion users, WhatsApp can seem unstoppable, but it has some weaknesses in its functionality—in the way it works. And, above all, it has one dealbreaker for many—its Facebook ownership. Signal App logo So, what are those functionality weaknesses? Well, there’s the continued lack of genuine support for multiple devices—the option to link apps on your phone, tablet and PC to a single account. Then there’s the serious flaw in its backup option, which is required to transfer message history to a new phone. Those back-ups fall outside WhatsApp’s end-to-end encryption—and that’s a critical issue. WhatsApp voice and video calling are excellent—fully encrypted, perfectly integrated with its messaging, single-click calls for the groups we use daily. But those calls—video or voice—are constrained to our smallest screen devices.