It can be used for vocabulary practice for beginners of Japanese. It is structured in a similar way to lessons such as Minna no Nihongo, Daichi, Marugoto, etc. It can be played alone or with friends.
The basic way to play is that first, one person puts their iPad (or smartphone) above their head so that they cannot see the screen of the smartphone from themselves. Then, another person looks at the word displayed on the smartphone and gives a clue for that word. The second person will look at the word on the phone and give a clue to the word, but do not say the word directly. Then, guess what word is being explained and guess the displayed word. If you guess correctly, you must tip the iPad forward. If you tip it forward, you get a point. Then you move on to the next question. If you fail to guess correctly, you move the iPad backward and move on to the next question.
There are various ways to give hints. You can give hints in Japanese, in your native language, or with gestures.