Tatar Trainer is an Android application developed by rebus.ws. This free app falls under the Education & Reference category. It is a vocabulary trainer for Tatar or Russian words that helps users memorize words by guessing the correct pairs. The app presents two columns, where users can select an Tatar or Russian word in one column, followed by the corresponding word in the other column. If the translation is correct, the pair of words will disappear.

The app also has a feature where words that are guessed correctly 10 times will be marked as learned and will not appear again. Users can view this list of learned words in the main menu by clicking on "Learned." Tatar Trainer is an excellent tool for those who want to improve their vocabulary in Tatar or Russian.