It is absolutely bizzare that I cannot use Whatsapp app on my phone and tablet at the same time. I have to do the stupid Whatsapp Web thing on the tablet which is a terrible experience in anyone's opinion. Facebook syncs messages on all existing devices without any issues but somehow it is an impossible feature to be included in Whatsapp. That being said I haven't seen any developement in Whatsapp since the past 2 years.