Games

Grammar
Puzzle English
This game improves your grammar skills. You'll need to create a new sentence using a list of the given words.
Translation
Sprint
This game teaches you to translate words from English to russian language quickly. This game uses words, that you have already learnt
Translation
Savannah
This game helps to improve your understanding of English speech, and also improves your skill of translation of the words.
Spelling
Hangman
This cheerful game tests your skill of understanding of the definition of the word. It also improves your mercy.
Pronunciation
Speak It
This game improves your speaking skills good enough for Google recognition of the speech.
Hearing
Audiocall
This game improves your skill of understanding of the English speech while listening to it.

Algorithm

This algorythm is inpired by the “Spaced repetition” methodology. It is similar to “Leitner system”, but has several differences.

Spaced repetition
Spaced repetition is an evidence-based learning technique that is usually performed with flashcards. Newly introduced and more difficult flashcards are shown more frequently while older and less difficult flashcards are shown less frequently in order to exploit the psychological spacing effect. The use of spaced repetition has been shown to increase rate of learning.

Leitner system
In this method flashcards are sorted into groups according to how well the learner knows each one in the Leitner's learning box. The learners try to recall the solution written on a flashcard. If they succeed, they send the card to the next group. If they fail, they send it back to the first group.

Algorithm differentiators
In this particular algorithm we based on following approach:

5 level word knowing: 0, 20, 40, 60, 80, 100 (scoring model)
In case if correct answer provided during training or game knowledge of current world will be promoted on next level
In case if incorrect answer provided during training or game knowledge of current world will be demoted to previous level
Each world have 20 score by default
Each level have different time interval for next repetition: 0 – 10 sec, 20 – 5 min, 40 – 20 min, 60 – 1 day, 80 – 1 week, 100 – 1 month

Illustration