in hard play option you can customize for how much time you want the application to question you. And for adding a little bit difficulty you can select for how much time one question will be displayed to you. in addition to that you can also select multiple tables from which the questions will be asked and you can also select the randomize option so the questions will be asked randomly.
if you use this application for a month and practice daily for 10-15 min. you can memorize all tables up to 30.
please give rating if you like the app..