Blood donation app

My app involves rewarding youth for donating blood. This is done through social media and local companies. For example, someone might donate blood, then on Facebook they would be announced their reward (such as one free meal for 12 weeks), with thanks to the company. I want the app to start simple to test problem validation. Features would require a link to Facebook, so we could tag the recipient and the company, and also not reward them until the post is liked. This would transfer to the app, where they will have the voucher - ready for one time use. Because you can only donate blood every 12 weeks, I want 12 weekly rewards, and the post must stay liked throughout and can't be used all at once. The voucher itself is still Beta, in that a simple recognition is required and discussed with the companies personally at the start. I want to start small, so location services are not required at this point in time. Simple, block functionality and one time use vouchers, statistics tracking (such as value saved, lives saved from donating, time until donating again, etc) are all that is required at the start. The reward must be confirmed after actually donating. This can be through QR codes at the start.