The flashcards in the iOS app have started showing the answers before the questions. Not only does this rather spoil the point, but it is visually very unsettling as the answer screen flashes by on the way to the question screen.
Oh no! So sorry about that. This must be a bug related to some updates we made today, we’re on it, should be resolved in a few minutes. Thanks for reporting 
Ok, that problem is fixed, but now I’m getting red or green flashing “lights” on selecting the cross or tick. This remains visually very disturbing. Oddly, it is only happening about 50% of the time.
I left the app in order to avoid becoming ill, only to find that the main, web-browser, site is doing the same thing.
The sequence is: select tick - screen goes blank - green square flashes for a very small fraction of a second - next question appears.
Hey coljay, thanks for pointing this out to us. The issue should be fixed