Integrate Google In-App Purchase with Counter

Integrate Google In-App Purchase System with Timer/Counter. Project Detail: Integrate Google In-App "digital goods" purchase system that tracks the numbers of minutes used. When minutes expire the end-user will be required to buy more minutes via Google In-App purchase. How it works: When user attempts to "start session" via Android app (this is step prior to accessing the LED light). The app will verify if user has enough minutes (credit). If not, user must buy more minutes. User can purchase minutes via the appp (I will supply .psd /artwork of this screen), which will have some options to buy minutes something like this: 20 minutes $1.99 40 minutes $2.49 60 minutes $3.49 Example: User has 10 minutes and sets timer (counter) to 15. App will require user to purchase additional minutes. On the main menu there will be a counter [ 0 minutes ] or [15 minutes] of whitening. I will supply .PSD file of artwork. Key notes: - New downloads of app will include 5 minutes of FREE minutes. - App must save # of minutes to a counter ("set timer") and as minutes used under teeth whitening LED light, minutes as used. Once depleted or if user requests more minutes than what is available per the counter. The app will prompt use to buy more minutes.