pretty good simple but effective practising tool. one of the better i have tried. just the numbers on your screen and a number pad. Can be improved by adding users/stats, practise in order from 1-10 and learning tables etc.
+ Some optimisations for tablets
+ Nice school picture
+ Crash on tablets (in landscape mode) solved.
+ Now also plus minus and devide-by (enable it in the settings)
+ also negative number (enable it in the settings)