Logitech's K480 multi-device keyboard provides supreme functionality for power users of any level. Fitted with a tablet and phone stand, the keyboard easily switches between three devices for quick access.
At first, I thought Logitech's design seemed a bit clunky, but for my use case it has ended up being perfect. While certainly portable, I wouldn't recommend this as a throw in your bag and keep with your iPad type of keyboard (there are plenty others much better suited to that).
What this has helped me with, though, is wrangling my interactions between my main work computer and the iPad I keep up at all times. The iPad typically displays my todos or personal email, while I use my main screen to focus solely on work. With the switch on the top left, I can quickly switch between the two devices and not miss a beat.
Even better, when at home, I pair it with my Windows machine, and it still keeps chugging along when used cross-platform. It's a well-thought out piece that has increased workflow and should do the same for you.