This app is built around a learning technique called spaced repetition.
Instead of reviewing a word many times in a short period, you review it several times over increasing intervals. At first, the word comes back quickly. Then, as you remember it better, the app waits longer before showing it again.
In this app, each word is reviewed up to 8 times. With each correct answer, the time before the next review increases. By the end of this process, the word is meant to stay in your long-term memory.
Spaced repetition is based on how memory works.
When you learn something new, your brain quickly starts to forget it. This is known as the “forgetting curve.” However, every time you successfully recall the information, your memory becomes stronger.
Reviewing something just before you’re about to forget it is the most effective way to learn. It tells your brain: this information is important, keep it.
This idea has been studied for over a century. Psychologist Hermann Ebbinghaus first described the forgetting curve, and many modern studies confirm that spaced repetition improves long-term memory much more than simple repetition.
Hermann Ebbinghaus’ forgetting curve
In short:
Spaced repetition finds that “right time” for you.
Each word you add starts at level 0.