| Quarterly financial information | 
    |  |  |  | Quarter
                                         Ended 31 July |  |  |  | Quarter
                                         Ended 31 Oct |  |  |  | Quarter
                                         Ended 31 Jan |  |  |  | Quarter
                                         Ended 30 April |  |  
    | 2015 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Net revenue |  | $ |  |  |  | $ |  |  |  | $ |  |  |  | $ |  |  |  
    | Cost of revenue |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Gross profit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Operating expenses |  |  | 1,583,160 |  |  |  | 6,200,845 |  |  |  | 1,456,554 |  |  |  | 4,020,176 |  |  
    | Other income (expenses), net |  |  | (1,664 | ) |  |  | 3,336,402 |  |  |  | (1,496 | ) |  |  | (213 | ) |  
    | Net loss |  | $ | (1,584,824 | ) |  | $ | (2,864,443 | ) |  | $ | (1,458,050 | ) |  | $ | (4,020,389 | ) |  
    | Net loss per common share, Basic and Diluted |  | $ | (0.00 | ) |  | $ | (0.01 | ) |  | $ | (0.00 | ) |  | $ | (0.01 | ) |      
    |  |  |  | Quarter
                                         Ended 31 July |  |  |  | Quarter
                                         Ended 31 Oct |  |  |  | Quarter
                                         Ended 31 Jan |  |  |  | Quarter
                                         Ended 30 April |  |  
    | 2014 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Net revenue |  | $ |  |  |  | $ |  |  |  | $ |  |  |  | $ |  |  |  
    | Cost of revenue |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Gross profit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Operating expenses |  |  | 1,400,691 |  |  |  | 448,570 |  |  |  | 681,080 |  |  |  | 16,448,801 |  |  
    | Other income (expenses), net |  |  | (3,265,676 | ) |  |  | (5,209,500 | ) |  |  | 222,308 |  |  |  | (22.010 | ) |  
    | Net loss |  | $ | (4,666,367 | ) |  | $ | (5,658,070 | ) |  | $ | (458,772 | ) |  | $ | (16,470,811 | ) |  
    | Net loss per common share, Basic and Diluted |  | $ | (0.01 | ) |  | $ | (0.01 | ) |  | $ | (0.00 | ) |  | $ | (0.03 | ) |    |