Why do you remember an answer you worked out better than one you just read?
An answer you produce yourself sticks harder than the same answer handed to you.
When you generate information yourself - filling a blank, guessing a word, working out a step - you remember it better than if you just read the finished version. Producing the answer forces effortful processing and lays down more paths back to the memory, even when the act of reading feels easier and more complete.
You will recall a new colleague's name far longer if you try to recall it before someone tells you, instead of just reading it off their name tag.
Make yourself produce the answer before you check it - the effort is what cements the memory.
This is why the app makes you answer first instead of showing you the card - you are meant to generate, not skim.
Generate, do not just read: the brain keeps what it had to build.
Learn the idea and practice English at the same time.