Hurling Buddy App

Just want to create a very simple app for players practicing on their own against a wall. the idea being to help them speed up their play and to expand their cognitive thought process while practicing on their own. (basically put them under a bit of mental pressure while they are hitting the ball against the wall!) should be a very simple design (have included a fairly crude drawing of how the gui would function) Home page would include 3 variables and a "Go" button. The 3 variables would be "Distance" which you could set to 5,8,12 or 20 "Targets" which could be set to 1,2,3,4 or 5 "Target Type" which could be set to Colours, numbers or shapes. once these have been selected and the users presses "Go" then the app will begin audibly generating the target type. so for example, the users has selected 4 targets ( he has created 4 different targets on a wall) and has selected Target Type to be numbers (he has numbered them 1-4). the app will then start calling out numbers 1-4 in a random manner. the last number that the user has heard before he strikes will be the target he must aim for. this will help increase the cognitive pressure on the user and they may be forced to change target at the very last second. the distance setting may be used to determine how many targets are called per second on average or something to that effect. it may even be redundant or just used as placebo