Simple Russian boy-bot Vasya explains English in a simple way. Vasya teaches to be a «predictable foreigner»: to make mistakes so that other peoples can understand you. Also i decreases stress level. I feel free to make mistakes and so I don't afraid to learn English. This process is becoming simple and funny conversation with laughable bot. Vasya doesn't skimp on praise. He gives you little tasks you can finish and always compliments you. Chatting with him you don't feel yourself like a loser. But what's more important for me, Vasya is very logical person. He uses causal relationship, system vocabulary and if-else constructions. If you are a technical specialist you will be glad to have such a teacher))
In general, Vasya is a close friend in my iPhone.