Android tablet prize wheel app

I need to manage prize giveaway inventory using an Android tablet. This project is two parts: 1 - The on-tablet action needs to be easy to use, with simple graphics and colors (I will provide RGB values for colors and font specifics). Users will "spin" an onscreen wheel either by tapping or swiping the screen to start and stop the wheel animation. The wheel should come to a stop on a slice that identifies the prize won. 2 - Inventory management - the app needs to manage prize inventory. Our staff will enter the type and number of available prizes (example: T-shirts, 100), and as prizes are awarded, quantity should be subtracted from the total available. When the quantity = 0, the prize should not be available for winning on the wheel - either the slice with that prize should disappear, or the wheel should not be allowed to stop on that slice. There will be no more than 8 individual prizes to be given away, with quantities up to 500 per prize.