The app has three screens, with the Number´s screen you will be able to improve your understanding of the numbers, in the spell´s screen you will may improve your comprehension of the abecedary and in the Word's screen you can improve your comprehension of words.
The app will choose a random number between 1 and 10.000.000 and you will have to write it, It will report you if you have written this correctly (you can change this range by the adjustment´s screen).
The app will spell a word between 46.280 which has (you can choose the size word to spell).
The app pronounced a word and you have to write to check if you have understand it, now it has 585 words.
To get a better experience with the app I advise to install the app Google Speech Synthesis ENG-USA voice, it will make possible to install the voices in high quality of English (United Kingdom) and English (United States).
Because of using high quality voices the program requires more time to start