Context, not flashcards
You type the missing word, so you recall it actively — and you see the inflected form the sentence actually uses, not just the dictionary entry.
Words stick when they come with a sentence
LingoLeap never shows you a bare word and its translation. Every word arrives inside a real sentence with one gap in it, and comes back later in a sentence you have not seen before.
Timed to what you remember
Every word comes back just before you would have forgotten it, sooner or later depending on how you answered. You never grade yourself.
New sentence every time
Memory is tied to the word, not to one sentence, so a word you are learning keeps reappearing in fresh contexts until it sticks.