The Mr Football game is free to play, but it also has some paid features which are mostly aimed at speeding up the season. The most cost-effective way of revving up your seasonal player development and bolstering your permanent collection of Legend cards is in unlocking the Premium track on the Drills.
In addition to the free track at the top of the Drills page, there is a second track underneath which can only be unlocked by paying real world currency or rubies. The Premium track is unlocked for a period of time; if you unlock it after the period opens, you can collect all the previously-earned rewards on the track. You must continue to play the game through that period to earn all the rewards. Note: it is possible to earn enough rubies in one period to unlock the Premium track in the following period – thus, you may only need to pay real world money once.
There are a number of periods during each game season, with themes corresponding to the time of year in the real footy season and ending with an Epic series of events.”