Brain pusher makes regular training in mental arithmetic possible. The lite version uses all day small multiplication exercises from primary/elementary school.
You will find an analysis of your results and success under "your status". You will find information about the tasks under game options.
Further versions of brain pusher are available in the itunes store.
Exercise:
multiplication:
easy: numbers up to 100 - 5 minutes per exercise
normal: numbers up to 100 - 1 minute per exercise
hard: numbers up to 100 - 30 seconds per exercise