1. http://www.garcard.com/nikeplus.php.
2. https://www.higi.com.
3. http://forbes.com/sites/stevenbertoni/2014/12/08/oscarhealth-using-misfit-wearables-to-reward-fit-customers.
4. http://technologyreview.com/news/516176/healthinsurers-app-helps-users-track-themselves.
5. https://en.bitcoinwiki.org/wiki/Simplified_Payment_Verification.