I am looking to implement membership card functionality inside a mobile application for a local coffee shop. The idea is to make payments at the point of sale, and deduct the amount from the client's prepaid account.I was looking into NFC functionality, but only a few devices support them (and most are not available in Montreal yet).The other idea is to use the Bump API, which would work great for iOS and Android.The last resort would be to use Bluetooth somehow.Any thoughts on any of these approaches, or for those who have tried this, any pros and cons for these ideas.
Bluetooth or Bump API for membership card functionality?
mobile
Have you considered using a plain old bar-code?  It's immune to 'sniffing', people understand how it works (at least much more than NFC or Bump), and it works on pretty much every device.  It would also make it very easy to code the app (and also make it not even require a phone, you could just use a key-chain or wallet card).  My local supermarkets both just use bar-code based membership cards, and each have an app with the ability to store those cards on the phone.  The benefit for bar-code based membership cards would be also the ability to scan/store the bar-codes in the app of the user's choosing, as there are some membership card storage apps already on the market, and you wouldn't have to duplicate functionality for users of said applications, they could store the cards and display the bar-code as they choose.  Until NFC becomes ubiquitous (if ever), I'd just go with a bar-code.