Cool!
Can you add an option to cycle through a chosen number of consecutive challenges, rather than one at a time? Currently in the challenge stage: Once you you provide an answer whether correct or incorrect, you must back out and begin again to receive another challenge. It would be great that if once you have your answer, it continued to cycle through a a pre-selected amount of challenges ( 5, 10, 20 etc. ). In this way, it would provide an exercise of mental stamina. Perhaps this option can configured in the settings, along with the option that allows for the setting of time intervals for the numbers.