In my search for good keyboard that support AMOLED mode, I found out about FlorisBoard which looks perfect to me. It even supports Halmak Keyboard Layout, which I didn't expect to find at any Android Keyboard.
Which make me ask, How is this keyboard not popular?
I've become dependent on SwiftKey. Unfortunately, it's invasive. I block network access on the app. It works great without it. It adjusts sensitivity and accuracy based on your typing habits, fixing mistakes over time that I make incessantly on other keyboards.