The Big Challenge Verb Ace is a game app (it is also available as a website). It was developed in order to help the students learn irregular verbs. It gives them the possibility to practice the infinitive, simple past and past participle forms while having fun. It is available in 10 different languages and you can choose the adjusted to your learners level of difficulty.
What is more, there are two more The Big Challege’s apps: The Big Challenge Quiz and The Big Challenge Yes No Game. Both of them were developed to practice English as a second language. You have an access to more than 10 000 questions (grammar, vocabulary, pronunciation, culture etc.). Again, you can adjust the level of difficulty.